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  • 1.
    Ali Malik, Muhammad
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Gatto, Emanuela
    University Roma Tor Vergata.
    Macken, Stephen
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    DiNatale, Corrado
    University Roma Tor Vergata.
    Paolesse, Roberto
    University Roma Tor Vergata.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Imaging fingerprinting of excitation emission matrices2009In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 635, no 2, 196-201 p.Article in journal (Refereed)
    Abstract [en]

    The spectral fingerprinting of the excitation emission matrix (EEM) of fluorescent substances is demonstrated using polychromatic light sources and tri-chromatic image detectors. A model of the measured fingerprints explaining their features and classification performance, based on the polychromatic excitation of the indicators is proposed.

    Substantial amount of spectral information is retained in the fingerprints as corroborated by multivariate analysis and experimental conditions that favor such situation are identified.

    In average, for five different substances, the model shows a fitting goodness measured by the Pearsons r coefficient and the root mean square deviation of 0.8541 and 0.0247 respectively, while principal component classification patterns satisfactorily compare with the EEM spectroscopy classification and respectively explain 96% and 93% of the information in the fist two principal components.

    The measurements can be performed using regular computer screens as illumination and web cameras as detectors, which constitute ubiquitous and affordable platforms compatible with distributed evaluations, in contrast to regular instrumentation for EEM measurements.

  • 2.
    Ali Soomro, Razium
    et al.
    University of Bristol, England; University of Sindh, Pakistan.
    Nafady, Ayman
    King Saud University, Saudi Arabia; Sohag University, Egypt.
    Hallam, Keith Richard
    University of Bristol, England.
    Jawaid, Sana
    University of Sindh, Pakistan.
    Al Enizi, Abdullah
    King Saud University, Saudi Arabia.
    Tufail Hussain Sherazi, Syed
    University of Sindh, Pakistan.
    Sirajuddin,
    Univ Sindh, Natl Ctr Excellence Analyt Chem, Jamshoro 76080, Pakistan.
    Ibupoto, Zafar Hussain
    Univ Sindh, Dr MA Kazi Inst Chem, Jamshoro 76080, Pakistan.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Highly sensitive determination of atropine using cobalt oxide nanostructures: Influence of functional groups on the signal sensitivity2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 948, 30-39 p.Article in journal (Refereed)
    Abstract [en]

    This study describes sensitive determination of atropine using glassy carbon electrodes (GCE) modified with Co3O4 nanostructures. The as-synthesised nanostructures were grown using cysteine (CYS), glutathione (GSH) and histidine (HYS) as effective templates under hydrothermal action. The obtained morphologies revealed interesting structural features, including both cavity-based and flower-shaped structures. The as-synthesised morphologies were noted to actively participate in electro-catalysis of atropine (AT) drug where GSH-assisted structures exhibited the best signal response in terms of current density and over-potential value. The study also discusses the influence of functional groups on the signal sensitivity of atropine electro-oxidation. The functionalisation was carried with the amino acids originally used as effective templates for the growth of Co3O4 nanostructures. The highest increment was obtained when GSH was used as the surface functionalising agent. The GSH-functionalised Co3O4-modified electrode was utilised for the electro-chemical sensing of AT in a concentration range of 0.01 -0.46 mu M. The developed sensor exhibited excellent working linearity (R-2 = 0.999) and signal sensitivity up to 0.001 mu M of AT. The noted high sensitivity of the sensor is associated with the synergy of superb surface architectures and favourable interaction facilitating the electron transfer kinetics for the electro-catalytic oxidation of AT. Significantly, the developed sensor demonstrated excellent working capability when used for AT detection in human urine samples with strong anti-interference potential against common co-existing species, such as glucose, fructose, cysteine, uric acid, dopamine and ascorbic acid. (C) 2016 Elsevier B.V. All rights reserved.

  • 3.
    Alimelli, Adriano
    et al.
    Dept of Electronic Engineering University of Rome.
    Filippini, Daniel
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Paolesse, Roberto
    dept of Chemical science and technology University of Rome.
    Moretti, Simonetta
    Instituto sperimentale per l´enologia.
    Ciolfi, Gaetano
    Instituto sperimentale per l´enologia.
    D´Amico, Arnaldo
    Dept. of Electronic Engineering University of Rome.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Di Natale, Corradeo
    Dept. of Electronic Engineering University of Rome.
    Direct quantitative evaluation of complex substances using computer screen photo-assisted technology: The case of red wine2007In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 597, 103-112 p.Article in journal (Refereed)
  • 4. Alimelli, Adriano
    et al.
    Pennazza, Giorgio
    Santonico, Marco
    Paolesse, Roberto
    University of Rome, Italy.
    Filippini, Daniel
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    D´Amico, Arnaldo
    University of Rome, Italy.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Di Natale, Corrado
    University of Rome, Italy.
    Fish freshness detection by a computer screen photoassisted based gas sensor array2007In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 582, no 2, 320-328 p.Article in journal (Refereed)
    Abstract [en]

    In the last years a large number of different measurement methodologies were applied to measure the freshness of fishes. Among them the connection between freshness and headspace composition has been considered by gas chromatographic analysis and from the last two decades by a number of sensors and biosensors aimed at measuring some characteristic indicators (usually amines). More recently also the so-called artificial olfaction systems gathering together many non-specific sensors have shown a certain capability to transduce the global composition of the fish headspace capturing the differences between fresh and spoiled products. One of the main objectives related to the introduction of sensor systems with respect to the analytical methods is the claimed possibility to distribute the freshness control since sensors are expected to be "portable" and "simple". In spite of these objectives, until now sensor systems did not result in any tool that may be broadly distributed. In this paper, we present a chemical sensor array where the optical features of layers of chemicals, sensitive to volatile compounds typical of spoilage processes in fish, are interrogated by a very simple platform based on a computer screen and a web cam. An array of metalloporphyrins is here used to classify fillets of thawed fishes according to their storage days and to monitor the spoilage in filleted anchovies for a time of 8 h. Results indicate a complete identification of the storage days of thawed fillets and a determination of the storage time of anchovies held at room temperature with a root mean square error of validation of about 30 min. The optical system produces a sort of spectral fingerprint containing information about both the absorbance and the emission of the sensitive layer. The system here illustrated, based on computer peripherals, can be easily scaled to any device endowed with a programmable screen and a camera such as cellular phones offering for the first time the possibility to fulfil the sensor expectation of diffused and efficient analytical capabilities. © 2006 Elsevier B.V. All rights reserved.

  • 5.
    Artursson, Tom
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Spångéus, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Holmberg, Martin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Variable reduction on electronic tongue data2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 452, no 2, 255-264 p.Article in journal (Refereed)
    Abstract [en]

    Reduction of the number of variables in data from a so-called electronic tongue contributes to simpler model calculations and less storage requirements. In this study, we have developed a model for this purpose. This model describes the response from the electrodes in the electronic tongue with two exponential functions plus a constant term, i(t) = k + kf e-ta + kc e-tß, where t is the time. From the model, five parameters which describe the signal are extracted. These parameters can be used as inputs instead of the original signal to any multivariate algorithm. The results show that the variables obtained are at least as good as the original data to separate between different classes, even though the number of parameters has been reduced between 80 and 199 times. © 2002 Elsevier Science B.V. All rights reserved.

  • 6.
    Arwin, Hans
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Optics .
    Piacham, Theeraphon
    Pure and applied biochemistry Lunds universitet.
    Josell, Åsa
    Pure and applied biochemsitry Lunds universitet.
    Prachayasittikul, Virapong
    Department of Clinical Microbiology Mahidol University, Bangkok.
    Ye, Lei
    Pure and applied biochemistry Lunds universitet.
    Molecularly imprinted polymer thin films on quartz crystal microbalance using a surface bound photo-radical initiator2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 536, 191-196 p.Article in journal (Refereed)
  • 7.
    Beni, Valerio
    et al.
    Tyndall National Institute, University College Cork, Ireland.
    Collins, Gilian
    Tyndall National Institute, University College Cork, Ireland.
    Arrigan, Damien
    Tyndall National Institute, University College Cork, Ireland.
    Investigation into the voltammetric behaviour and detection of selenium(IV) at metal electrodes in diverse electrolyte media2011In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 699, no 2, 127-133 p.Article in journal (Refereed)
    Abstract [en]

    The voltammetric behaviour of selenium(IV) was studied at platinum and gold electrodes in sulphuricacid, perchloric acid and potassium chloride media as a basis for its voltammetric detection. The bestvoltammetric behaviour was recorded at gold electrodes with perchloric acid as the supporting electrolyte.The concomitant presence of metals, such as copper or lead, and of model biomolecules, suchas bovine serum albumin, in the solution resulted in a deterioration of the electrochemical response forselenium(IV). Quantitative detection of selenium(IV) by square wave anodic stripping voltammetry atboth a millimetre-sized gold disc electrode and a microband electrode array revealed linear responsesto selenium concentration in the ranges 5–15 M and 0.1–10 M, respectively, with 60 s preconcentration.The sensitivities were 6.4 A M−1 cm−2 and 100 A M−1 cm−2 at the disc and the microband array,respectively. The detection limit at the microband electrode array was 25 nM, illustrating the potentialityof such microelectrodes for the development of mercury-free analytical methods for the trace detectionof selenium(IV).

  • 8.
    Beni, Valerio
    et al.
    NMRC, University College, Cork, Ireland.
    Newton, Hazel
    NMRC, University College, Cork, Ireland.
    Arrigan, Damien
    NMRC, University College, Cork, Ireland.
    Hill, Martin
    NMRC, University College, Cork, Ireland.
    Lane, William
    NMRC, University College, Cork, Ireland.
    Mathewson, Alan
    NMRC, University College, Cork, Ireland.
    Voltammetric behaviour at gold electrodes immersed in the BCR sequential extraction scheme media: Application of underpotential deposition–stripping voltammetry to determination of copper in soil extracts2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 502, no 2, 195-206 p.Article in journal (Refereed)
    Abstract [en]

    The development of mercury-free electroanalytical systems for in-field analysis of pollutants requires a foundation on the electrochemicalbehaviour of the chosen electrode material in the target sample matrices. In this work, the behaviour of gold working electrodes in the mediaemployed in the BCR sequential extraction protocol, for the fractionation of metals in solid environmental matrices, is reported. All three ofthe BCR sequential extraction media are redox active, on the basis of acidity and oxygen content as well as the inherent reducing or oxidisingnature of some of the reagents employed: 0.11M acetic acid, 0.1M hydroxylammonium chloride (adjusted to pH 2) and 1M ammoniumacetate (adjusted to pH 2) with added trace hydrogen peroxide. The available potential ranges together with the demonstrated detection oftarget metals in these media are presented. Stripping voltammetry of copper or lead in the BCR extract media solutions reveal a multi-peakbehaviour due to the stripping of both bulk metal and underpotential metal deposits. A procedure based on underpotential deposition–strippingvoltammetry (UPD-SV) was evaluated for application to determination of copper in 0.11M acetic acid soil extracts. A preliminary screeningstep in which different deposition times are applied to the sample enables a deposition time commensurate with UPD-SV to be selected sothat no bulk deposition or stripping occurs thus simplifying the shape and features of the resulting voltammograms. Choice of the suitabledeposition time is then followed by standards addition calibration. The method was validated by the analysis of a number of BCR 0.11Macetic acid soil extracts. Good agreement was obtained been the UPD-SV method and atomic spectroscopic results.

  • 9.
    Beni, Valerio
    et al.
    Tyndall National Institute, University College, Cork, Ireland.
    Ogurtsov, Vladimir
    Tyndall National Institute, University College, Cork, Ireland.
    Bakunin, Nikolai
    Tyndall National Institute, University College, Cork, Ireland.
    Arrigan, Damien
    Tyndall National Institute, University College, Cork, Ireland.
    Hill, Martin
    Cork Institute of Technology, Bishopstown, Cork, Ireland.
    Development of a portable electroanalytical system for the stripping voltammetry of metals: Determination of copper in acetic acid soil extracts2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 552, no 1-2, 190-200 p.Article in journal (Refereed)
    Abstract [en]

    The development, characterisation and evaluation of a prototype portable electrochemical trace metal analyser are presented. The instrumentis a battery-powered microcontroller-based potentiostat, which implements anodic stripping voltammetry (ASV) at suitable sensor electrodes.It is capable of operating away from the laboratory, in the absence of an external power source and is usable by low-skilled personnel. Thedistinguishing feature of the instrument is its custom software, which enables sample pre-screening, data processing and sample dilution andstandard additions calculations to be carried out. The instrument has been evaluated by application of a methodology for the detection ofcopper in acetic acid soil extracts, both in the laboratory and in the field. Underpotential deposition staircase anodic stripping voltammetry(UPD-SCASV) of the copper at gold disk electrodes was used as a test method. There was good agreement between the instrument resultsand those from laboratory-based reference analytical methods for analyses carried out both in the laboratory and in the field.

  • 10.
    Carlsson, Jenny
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Mecklenburg, Michael
    nanoArc Corp, Newport Beach, CA, USA.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Danielsson, Bengt
    Pure and Applied Biochemistry, Lund University, PO Box 124, SE-22100 Lund, Sweden .
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Investigation of sera from various species by using lectin affinity arrays and scanning ellipsometry2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 530, no 2, 167-171 p.Article in journal (Refereed)
    Abstract [en]

    Serum proteins of different species and of different human blood groups exhibit various protein glycosylation patterns. Sera from human, pig, sheep and guinea pig have been applied to a panel of eight different lectins immobilized on a gold wafer. The biorecognition has been evaluated with scanning ellipsometry and the two-dimensional matrices obtained have been treated with image analysis and MVDA for evaluation. The results showed a clear difference in protein binding pattern between the different species and thereby separation of the different sera could be made. Dendograms indicate that human and pig sera are the most related of the four different sera investigated.

  • 11.
    Carlsson, Jenny
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Danielsson, Bengt
    Pure and Applied Biochemistry, Lund University, SE-22 100 Lund, Sweden .
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Biosensor discrimination of meat juice from various animals using a lectin panel and ellipsometry2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 547, no 2, 229-236 p.Article in journal (Refereed)
    Abstract [en]

    In this work, simple microcontact printed gold-wafers were used to make a lectin panel for investigation and discrimination of different meat juices from fresh meat of cattle, chicken, pig, cod, turkey and lamb. Seven different lectins were thus attached to gold surfaces using the streptavidin–biotin method. Lectins recognize and bind specifically to carbohydrate structures present on different proteins. The biorecognition was evaluated with null ellipsometry and the data obtained was related to an internal standard of lactoferrin. The data was evaluated with multivariate data analysis techniques to identify possible discrimination or grouping of data. Scanning ellipsometry was used for visualization of the binding pattern of the lectins and the meat juice proteins. The two-dimensional images obtained could be used to visualize the protein distribution, furthermore, to exclude anomalies. The results showed that the different meat juices from the six different species: cattle, chicken, pig, cod, turkey and lamb could be discriminated from each other. The results showed to be more repetitive for the mammalian meat juices. Using a simple model based on an artificial neuronal net, it was also possible to classify meat juices from the mammals investigated.

  • 12.
    Cavanillas, Santiago
    et al.
    University of Barcelona, Spain.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    A self-polishing platinum ring voltammetric sensor and its application to complex media2015In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 859, 29-36 p.Article in journal (Refereed)
    Abstract [en]

    A self-polishing voltammetric sensor was recently developed and has been applied to samples of urea, milk and sewage water. The polishing device continuously grinds a platinum ring electrode, offering a reproducible and clean electrode surface. Principal component analysis (PCA) and partial least squares (PLS) techniques were applied to interpret the data and to build prediction models. In an evaluation of samples with different urea concentrations, the grinding step allows for repeatable measurements, similar to those after electrochemical cleaning. Furthermore, for the determination of sewage water concentrations in drinking water and for the evaluation of different fat contents in milk samples, the polishing eliminates sensor drift produced by electrode fouling. The results show that the application of a self-polishing unit offers a promising tool for electrochemical studies of difficult analytes and complex media. (C) 2014 Elsevier B.V. All rights reserved.

  • 13.
    Chen, Chang
    et al.
    Huazhong University of Science and Technology, Peoples R China.
    Wohlfarth, Ariane
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences. National Board Forens Med, Linköping, Sweden.
    Xu, Hui
    Maternal and Child Health Hospital Hubei Prov, Peoples R China.
    Su, Dan
    Jiangxi University of Tradit Chinese Med, Peoples R China.
    Wang, Xin
    MassDefect Technology, NJ 08540 USA.
    Jiang, Hongliang
    Huazhong University of Science and Technology, Peoples R China.
    Feng, Yulin
    Jiangxi University of Tradit Chinese Med, Peoples R China.
    Zhu, Mingshe
    Bristol Myers Squibb, NJ 08543 USA.
    Untargeted screening of unknown xenobiotics and potential toxins in plasma of poisoned patients using high-resolution mass spectrometry: Generation of xenobiotic fingerprint using background subtraction2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 944, 37-43 p.Article in journal (Refereed)
    Abstract [en]

    A novel analytical workflow was developed and applied for the detection and identification of unknown xenobiotics in biological samples. High-resolution mass spectrometry (HRMS)-based data-independent MSE acquisition was employed to record full scan MS and fragment spectral datasets of test and control samples. Then, an untargeted data-mining technique, background subtraction, was utilized to find xenobiotics present only in test samples. Structural elucidation of the detected xenobiotics was accomplished by database search, spectral interpretation, and/or comparison with reference standards. Application of the workflow to analysis of unknown xenobiotics in plasma samples collected from four poisoned patients led to generation of xenobiotic profiles, which were regarded as xenobiotic fingerprints of the individual samples. Among 19 xenobiotics detected, 11 xenobiotics existed in a majority of the patients plasma samples, thus were considered as potential toxins. The follow-up database search led to the tentative identification of azithromycin (X5), alpha-chaconine (X9) and penfluridol (X12). The identity of X12 was further confirmed with its reference standard. In addition, one xenobiotic component (Y5) was tentatively identified as a penfluridol metabolite. The remaining unidentified xenobiotics listed in the xenobiotic fingerprints can be further characterized or identified in retrospective analyses after their spectral data and/or reference compounds are available. This HRMS-based workflow may have broad applications in the detection and identification of unknown xenobiotics in individual biological samples, such as forensic and toxicological analysis and sport enhancement drug screening. (C) 2016 Elsevier B.V. All rights reserved.

  • 14.
    Cheung, Kwan Yee
    et al.
    National University of Singapore.
    Mak, Wing Cheung
    National University of Singapore.
    Trau, Dieter
    National University of Singapore.
    Reusable optical bioassay platform with permeability-controlled hydrogel pads for selective saccharide detection2008In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 607, no 2, 204-210 p.Article in journal (Refereed)
    Abstract [en]

    A reusable optical bioassay platform using permeability-controlled hydrogel pads for selective saccharide detection has been developed. An optical glucose detection assay based on fluorescence resonance energy transfer (FRET) between dye-labeled dextran and Concanavalin A (ConA) was incorporated into hydrogel pads by entrapment. The hydrogel pads are constructed from hemispherical hydrogel attached onto hydrophobic surfaces of a microtiter plate. The resulted hemispherical hydrogel pads entrapping the sensing biological materials were further surface coated with polyelectrolyte multilayers through a Layer-by-Layer (LbL) self-assembly process to create a permeability-controlled membrane with nanometer thickness. The selective permeable LbL film deposited on the hydrogel surface allows small molecular weight analytes to diffuse into the hydrogel pads while the large molecular weight sensing biological molecules are immobilized. An encapsulation efficiency of 75% for the ConA/Dextran complex within the coated hydrogel pads was achieved and no significant leakage of the complex was observed. Glucose calibration curve with linear range from 0 to 10 mM glucose was obtained. Selective permeability of the hydrogel pads has been demonstrated by measurement of saccharides with various molecular weights. The LbL hydrogel pads could selectively detect monosaccharides (glucose, MW = 180) and disaccharides (sucrose, MW = 342) while polysaccharides (dextran, MW ∼ 70 kDa) cannot diffuse through the LbL layer and are excluded. LbL hydrogel pads allow regeneration of the FRET system with good signal reproducibility of more than 90% to construct a reusable and reagentless optical bioassay platform.

  • 15.
    DICKS, JM
    et al.
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,DIV BIOELECTRON,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    ASTON, WJ
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,DIV BIOELECTRON,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    DAVIS, G
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,DIV BIOELECTRON,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    MEDIATED AMPEROMETRIC BIOSENSORS FOR D-GALACTOSE, GLYCOLATE AND L-AMINO-ACIDS BASED ON A FERROCENE-MODIFIED CARBON PASTE ELECTRODE1986In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 182, 103-112 p.Article in journal (Refereed)
    Abstract [en]

    n/a

  • 16.
    ERASIN, BR
    et al.
    CRANFIELD UNIV,CRANFIELD BIOTECHNOL CTR,BEDFORD MK43 0AL,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    WHEATLEY, AD
    CRANFIELD UNIV,CRANFIELD BIOTECHNOL CTR,BEDFORD MK43 0AL,ENGLAND; .
    A FIXED-FILM BIOASSAY FOR THE DETECTION OF MICROPOLLUTANTS TOXIC TO ANAEROBIC SLUDGES1994In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 298, no 1Article in journal (Refereed)
    Abstract [en]

    Micropollutants in waste water streams can be a serious problem for the anaerobic digestion process. A short-term acute bioassay system is described for testing the effects of new and potentially toxic compounds on anaerobic digestion processes. Change in methanogenic activity was used as the monitored process parameter and the performance of intoxicated inocula was compared to activity prior to adding test compounds and to the activity of a parallel control assay. The performance of the bioassay was tested with chlorinated solvents and heavy metals. Trichloroethane caused a 50% reduction in methanogenic activity at 7 mg/l assay. The performance of suspended and fixed biomass assays were compared; the suspended growth was found to be five times more sensitive to trichloroethane. There was no clear inhibition with the heavy metals even at the highest concentration used (up to 750 mg Cu/l). The duration of assay was found to be an important parameter in the evaluation of anaerobic toxicity.

  • 17.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Preferential color substances and optimized illuminations for computer screen photo-assisted classification2006In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 5572006, 393-398 p.Article in journal (Refereed)
  • 18.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Spectroscopic information retained in screen photo-assisted techniques2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 521, no 2, 237-244 p.Article in journal (Refereed)
    Abstract [en]

    The computer screen photo-assisted technique (CSPT), a recently reported method for characterization of colorimetric assays, has been modeled and the ability of the technique to retain key spectral features has been determined. The robustness of CSPT to operate with different kind of screens is demonstrated and a physical explanation of the result is provided. Simulated CSPT transmittances corroborate experimental results, and enable comparison with standard methods for qualitative and quantitative evaluation. © 2004 Elsevier B.V. All rights reserved.

  • 19.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Computer screen photo-excited surface plasmon resonance imaging2008In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 625, no 2, 207-214 p.Article in journal (Refereed)
    Abstract [en]

    Angle and spectra resolved surface plasmon resonance (SPR) images of gold and silver thin films with protein deposits is demonstrated using a regular computer screen as light source and a web camera as detector. The screen provides multiple-angle illumination, p-polarized light and controlled spectral radiances to excite surface plasmons in a Kretchmann configuration. A model of the SPR reflectances incorporating the particularities of the source and detector explain the observed signals and the generation of distinctive SPR landscapes is demonstrated. The sensitivity and resolution of the method, determined in air and solution, are 0.145 nm pixel-1, 0.523 nm, 5.13 × 10-3 RIU degree-1 and 6.014 × 10-4 RIU, respectively, encouraging results at this proof of concept stage and considering the ubiquity of the instrumentation. © 2008 Elsevier B.V. All rights reserved.

  • 20.
    HALL, GF
    et al.
    ; .
    BEST, DJ
    ; .
    TURNER, APF
    Cranfield University, UK.
    THE DETERMINATION OF P-CRESOL IN CHLOROFORM WITH AN ENZYME ELECTRODE USED IN THE ORGANIC-PHASE1988In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 213, no 02-jan, 113-119 p.Article in journal (Refereed)
    Abstract [en]

    n/a

  • 21.
    HENDRY, SP
    et al.
    CRANFIELD INST TECHNOL,CRANFIELD BIOTECHNOL CTR,CRANFIELD MK43 0AL,BEDS,ENGLAND; UNIV WITWATERSRAND,DEPT CHEM,JOHANNESBURG 2001,SOUTH AFRICA; .
    CARDOSI, MF
    CRANFIELD INST TECHNOL,CRANFIELD BIOTECHNOL CTR,CRANFIELD MK43 0AL,BEDS,ENGLAND; UNIV WITWATERSRAND,DEPT CHEM,JOHANNESBURG 2001,SOUTH AFRICA; .
    TURNER, APF
    Cranfield University, UK.
    NEUSE, EW
    CRANFIELD INST TECHNOL,CRANFIELD BIOTECHNOL CTR,CRANFIELD MK43 0AL,BEDS,ENGLAND; UNIV WITWATERSRAND,DEPT CHEM,JOHANNESBURG 2001,SOUTH AFRICA; .
    POLYFERROCENES AS MEDIATORS IN AMPEROMETRIC BIOSENSORS FOR GLUCOSE1993In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 281, no 3, 453-459 p.Article in journal (Refereed)
    Abstract [en]

    This paper describes the first successful application of polymeric ferrocenes as mediators in amperometric biosensors. The results have implications for the design of stable biosensors and bioelectronic devices involving electron transfer from oxidoreductases to electrode surfaces. The behaviour of two ferrocene polymers in enzyme electrodes was explored and a distinctive pH profile was noted. It is suggested that changes in either the enzyme conformation or the polymer in response to hydrogen ion concentration may explain the difference in behaviour between monomeric and polymeric ferrocenes.

  • 22.
    Herzog, Gregoire
    et al.
    Université de Lorraine, France.
    Beni, Valerio
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Stripping voltammetry at micro-interface arrays: A review2013In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 769, 10-21 p.Article in journal (Refereed)
    Abstract [en]

    In this article, a comprehensive overview of the most recent developments in the field of stripping voltammetryat regular micro-interfaces (both solid–liquid and liquid–liquid interfaces) is presented. Thisreview will report on the most conventional arrays of metallic micro-electrodes but also on the rapidlygrowing field of electrochemistry at arrays of micro-interfaces between two immiscible electrolyte solutions(ITIES). The main fabrication methods, together with some design considerations and diffusionphenomena at such interfaces are discussed. Main applications of micro-interface arrays are presentedincluding heavy metals detection at micro-electrode arrays and detection of organic molecules (aminoacids, vitamins, peptides and drugs) at the ITIES. Stripping analysis at micro-interface arrays is suitablefor the detection of analytes in several real media including water, soil extracts and biological fluids(blood and saliva) with high specificity, sensitivity (detection limits of nM, ppb level) and reliability.Stripping analysis at ITIES and micro-electrode arrays are two complementary approaches that havethe advantages of being cost effective, simple to use and easily adaptable to field measurement.

  • 23.
    Herzog, Gregoire
    et al.
    NMRC, University College, Cork, Ireland.
    Beni, Valerio
    NMRC, University College, Cork, Ireland.
    Dillon, Patrick
    NMRC, University College, Cork, Ireland.
    Barry, Thomas
    NMRC, University College, Cork, Ireland.
    Arrigan, Damien
    NMRC, University College, Cork, Ireland.
    Effect of humic acid on the underpotential deposition-strippingvoltammetry of copper in acetic acid soil extract solutions atmercaptoacetic acid-modified gold electrodes2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 511, no 1, 137-143 p.Article in journal (Refereed)
    Abstract [en]

    Electrochemical measurements were undertaken for the investigation of the underpotential deposition-stripping process of copper at bareand modified gold electrodes in 0.11M acetic acid, the first fraction of the European Union’s Bureau Communautaire de Références (BCR)sequential extraction procedure for fractionating metals within soils and sediments. Gold electrodes modified with mercaptoacetic acid showedhigher sensitivity for the detection of copper than bare gold electrodes, both in the absence and in the presence of humic acid in acetic acidsolutions, using the underpotential deposition-stripping voltammetry (UPD-SV) method. In the presence of 50 mg l−1 of humic acid, themercaptoacetic acid modified electrode proved to be 1.5 times more sensitive than the bare gold electrode. The mercaptoacetic acid monolayerformed on the gold surface provided efficient protection against the adsorption of humic acid onto the gold electrode surface. Variation of thehumic acid concentration in the solution showed little effect on the copper stripping signal at the modified electrode. UPD-SV at the modifiedelectrode was applied to the analysis of soil extract samples. Linear correlation of the electrochemical results with atomic spectroscopic resultsyielded the straight-line equation y (g l−1) = 1.10x − 44 (ppb) (R = 0.992, n = 6), indicating good agreement between the two methods.

  • 24.
    Holmin, Susanne
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Multivariate optimisation of electrochemically pre-treated electrodes used in a voltammetric electronic tongue2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 519, no 1, 39-46 p.Article in journal (Refereed)
    Abstract [en]

    The use of experimental design as a tool to optimise electrochemically cleaned electrodes applied in a voltammetric electronic tongue is described. A simple and quick activation of electrode surfaces is essential for this type of device, especially for on-line applications in industrial processes. The electronic tongue consisted of four metal electrodes, e.g. Au, Ir, Pt, and Rh in a three-electrode configuration. Current was measured as a function of large potential pulses of decreasing amplitude applied to each electrode. Preliminary results showed that electrochemical cleaning activated the electrode surfaces to similar extent as polishing. Settings of potential and time for each electrode was determined with experimental design in a solution containing 1.0 mM K 4[Fe(CN)6] in 0.1 M phosphate buffer (pH 6.8). Electrode surfaces were deactivated in-between measurements in a complex liquid, like tea. Optimal settings for potential and time in the electrochemical cleaning procedure at each electrode were chosen at recoveries of 100% (compared to polished electrodes). The recoveries were larger than 100% when too large potentials and times were applied. This could be explained by the fact that the electrode areas increased and therefore also the current responses. Principal component analysis (PCA) was used to investigate the stability of the electrode settings at 100% recoveries. No obvious trends of drift in the signals were found. © 2004 Elsevier B.V. All rights reserved.

  • 25.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Tongji University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai University, Peoples R China.
    Chen, Zhiwen
    Shanghai University, Peoples R China.
    Gao, Hong-Wen
    Tongji University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A logic gate-based fluorogenic probe for Hg2+ detection and its applications in cellular imaging2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 919, 85-93 p.Article in journal (Refereed)
    Abstract [en]

    A new colorimetric and fluorogenic probe (RN3) based on rhodamine-B has been successfully designed and synthesized. It displays a selective response to Hg2+ in the aqueous buffer solution over the other competing metals. Upon addition of Hg2+, the solution of RN3 exhibits a naked eye observable color change from colorless to red and an intensive fluorescence with about 105-fold enhancement. The changes in the color and fluorescence are ascribed to the ring-opening of spirolactam in rhodamine fluorophore, which is induced by a binding of the constructed receptor to Hg2+ with the association and dissociation constants of 0.22 x 10(5) M-1 and 25.2 mM, respectively. The Jobs plot experiment determines a 1: 1 binding stoichiometry between RN3 and Hg2+. The resultant "turn-on" fluorescence in buffer solution, allows the application of a method to determine Hg2+ levels in the range of 4.0-15.0 mu M, with the limit of detection (LOD) calculated at 60.7 nM (3 sigma/slope). In addition, the fluorescence turn-off and color fading-out happen to the mixture of RN3-Hg2+ by further addition of I- or S2-. The reversible switching cycles of fluorescence intensity upon alternate additions of Hg2+ and S2- demonstrate that RN3 can perform as an INHIBIT logic gate. Furthermore, the potential of RN3 as a fluorescent probe has been demonstrated for cellular imaging. (C) 2016 Elsevier B.V. All rights reserved.

  • 26.
    Hu, Zhang-Jun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Jiwen
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. Tongji University, Peoples R China.
    Wang, Hui
    Anhui University, Peoples R China.
    Zhang, Qiong
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Zhao, Meng
    Anhui University, Peoples R China.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Tian, Yupeng
    Anhui University, Peoples R China.
    Gao, Hongwen
    Tongji University, Peoples R China.
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. University of Macau, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A TPA-caged precursor of (imino)coumarin for "turn-on" fluorogenic detection of Cu+2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 933, 189-195 p.Article in journal (Refereed)
    Abstract [en]

    We strategize to utilize the precursors of (imino) coumarin fluorophores to deliver novel reactive Cu+ probes, where tris[(2-pyridyl)-methyl] amine (TPA) works as a reactive receptor towards Cu+. To verify this strategy, CP1, a representative probe and relevant sensing behaviors towards Cu+ are presented here. CP1 features good solubility and fast response for monitoring labile copper in aqueous solution and live cells. The sensing mechanism of CP1 is determined by HPLC titration and mass spectrometric analysis. The probe CP1 exhibits a 60-fold fluorescence enhancement and a detection limitation of 10.8 nM upon the detection of Cu+. CP1 is further applied for imaging labile copper in live cells. This work provides a starting point for future development of Cu+ probes, based on in situ formation of (imino) coumarin scaffolds, as well as their further investigations of copper signaling and biological events. (C) 2016 Elsevier B.V. All rights reserved.

  • 27. Ivansson, D.
    et al.
    Bayer, K.
    Mandenius, Carl-Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biotechnology .
    Quantitation of intracellular recombinant human superoxide dismutase using surface plasmon resonance2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 456, no 2, 193-200 p.Article in journal (Refereed)
    Abstract [en]

    An immunosensor assay for the quantitation of intracellular recombinant human superoxide dismutase (rhSOD) in Escherichia coli cultivations based on detection with surface plasmon resoance (SPR) is described. A monoclonal antibody for rhSOD was immobilized on a SPR dextran gold chip. Bacterial samples were sonicated and centrifugated prior to injection over the antibody chip for SPR detection. The assay time was 7min and allowed quantitation in the range of 1-64nM SOD in lysate samples with a precision of 1.1-3.4%. The assay was applied to monitor the concentration of rhSOD during E. coli bioreactor cultivations where the rhSOD production was induced by iso-propyl-b-D-thiogalactoside (IPTG). The assay allowed accurate monitoring of the production of rhSOD where the important phases in the product formation were possible to see. The report also discusses influence from sample preparation, SPR selectivity and sensitivity and quantitation limits. The assay proved to be fast, sensitive and accurate with low background effects from the dextran matrix of the SPR chip. ⌐ 2002 Published by Elsevier Science B.V.

  • 28.
    Ivarsson, Patrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering. Asko Cylinder AB.
    Kikkawa, Y.
    Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka 812-8581, Japan.
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Hojer, N.-E.
    Höjer, N.-E., Asko Cylinda AB, SE-534 82 Vara, Sweden.
    Hayashi, K.
    Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka 812-8581, Japan.
    Toko, K.
    Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka 812-8581, Japan.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Comparison of a voltammetric electronic tongue and a lipid membrane taste sensor2001In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 449, no 1-2, 59-68 p.Article in journal (Refereed)
    Abstract [en]

    An electronic tongue based on voltammetry and a multichannel lipid membrane taste sensor based on potentiometry are compared using two aqueous examples: detergents and teas. The electronic tongue consists of four electrodes of different metals, a reference electrode and a counter electrode. The measurement principle is based on pulse voltammetry in which current is measured during the change of the amplitude of the applied potential. The taste sensor is based on eight different lipid/polymer membranes. The voltage difference between the electrodes and an Ag/AgCl reference electrode is measured when the current is close to zero. The responses from the two sensors systems are treated separately with multivariate data analysis based on principal component analysis and then merged to examine if further information could be extracted. It is shown that although the two sensor systems are about equal in separation ability in the two cases, extra information can be gained by combination of the two sensor systems. © 2001 Elsevier Science B.V. All rights reserved.

  • 29.
    Jungar, Christina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, Faculty of Science & Engineering.
    Mandenius, Carl-Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biotechnology.
    Neoglycoconjugates as affinity ligands in surface plasmon resonance analysis2001In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 449, no 1-2, 51-58 p.Article in journal (Refereed)
    Abstract [en]

    Neoglycoconjugates, i.e. de novo synthesized conjugates of glycosides and carrier molecules such as proteins or polylipids, were used as affinity ligands in a surface plasmon resonance (SPR) biosensor assay. The affinity of the glycoconjugates, normally in the lower affinity range, was influenced by increasing the number of glycosides bound per carrier protein, the coupling chemistry, and the assay temperature. As a model system, albumin-conjugated A- and B-active blood group oligosaccharides with suitable linker molecules were chosen. Specific monoclonal antibodies were used as analytes to verify the interactive performance. Affinity kinetics of the systems were evaluated from the SPR biosensor data. The results demonstrate that neoglycoconjugates are a good alternative in presenting affinity ligands of small, specific molecules in SPR-based assays with retained specificity and bioavailability. ⌐ 2001 Elsevier Science B.V. All rights reserved.

  • 30. Kalman, E.-L.
    et al.
    Lofvendahl, A.
    Löfvendahl, A., Volvo Car Corporation, 98351 PV 1B, S-405 08, Göteborg, Sweden.
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Classification of complex gas mixtures from automotive leather using an electronic nose2000In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 403, no 1-2, 31-38 p.Article in journal (Refereed)
    Abstract [en]

    A semiconductor gas sensor array combined with a routine for pattern recognition - a so-called electronic nose - for the detection of gas emissions from the leather used in car compartments is described. The gas sensors are 10 metal oxide semiconductor field effect transistors (MOSFETs) with gates of thin, catalytic metals, and five semiconducting metal oxide sensors. The sensor array data are processed by multivariate means using principal component analysis (PCA) and are shown to give similar and add additional information compared to gas chromatography-mass spectrometry (GC- MS) and a human sensory panel. The total volatile organic compound concentration as measured by GC did not differ between good and bad samples and could therefore not be used as a quality control tool, whilst the electronic nose together with pattern recognition could readily discover the deviating samples with unusual emitting gases. This set-up could be useful in on-line quality monitoring systems to detect anomalies in incoming car interior trim materials.

  • 31.
    Krantz-Rülcher, Christina
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Stenberg, M.
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Electronic tongues for environmental monitoring based on sensor arrays and pattern recognition: A review2001In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 426, no 2, 217-226 p.Conference paper (Other academic)
    Abstract [en]

    The use of sensor arrays and pattern recognition applied to the obtained signal patterns for environmental monitoring are discussed in some detail. Different types of electronic tongues are described and evaluated for monitoring purposes. More specifically the performance of multielectrode arrays used for voltammetric analysis of aqueous samples is described. It is, e.g. shown how such an 'electronic tongue' can be used to monitor the quality of water in a production plant for drinking water. It is pointed out that the concepts of 'electronic noses' and 'electronic tongues' often predict a quality of a sample rather than giving exact information about concentrations of individual species. (C) 2001 Elsevier Science B.V.

  • 32.
    Kroger, S
    et al.
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Setford, SJ
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Assessment of glucose oxidase behaviour in alcoholic solutions using disposable electrodes1998In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 368, no 3, 219-231 p.Article in journal (Refereed)
    Abstract [en]

    Solvent resistant screen-printed three-electrode devices were employed to assess the behaviour of free and immobilised glucose oxidase in water-miscible organic solvent/aqueous buffer mixtures. Three alcoholic solvents were examined, methanol, ethanol and isopropanol. A rhodinised-carbon electrocatalyst was employed to facilitate hydrogen peroxide oxidation at a decreased operating potential. The devices had a linear response range of 1-10 mU GOX and allowed detection of down to 2 x 10(-14) mol GOX. The measurement of 0-1 (v/v) glucose in 30% (v/v) ethanol was achieved in 2 min using these highly storage-stable enzyme electrodes. Such devices are likely to have widespread applications in the diagnostic and on-line monitoring fields where rapid analysis in alcoholic matrices is desirable. (C) 1998 Elsevier Science B.V. All rights reserved.

  • 33.
    Kroger, S
    et al.
    CRANFIELD UNIV,CRANFIELD BIOTECHNOL CTR,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    Turner, APF
    Cranfield University, UK.
    Solvent-resistant carbon electrodes screen printed onto plastic for use in biosensors1997In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 347, no 02-janArticle in journal (Refereed)
    Abstract [en]

    A three electrode design using solvent resistant materials is reported, enabling the production of screen printed electrodes for use in biosensor applications involving water-miscible organic solvents. Heat stabilised polyester sheets were used as base materials in combination with carbon basal tracks and an epoxy-based polymer protective coating. The new electrodes avoid problems with solvent induced baseline shifts displayed by conventional screen-printed electrodes. The material for the underlying basal track has been changed from silver to carbon ink to reduce the number of materials involved in the production and avoid possible interferences. In addition, the design is readily applied in biosensor applications. Different methods for the incorporation of a rhodium catalyst are discussed. The application of the electrode system modified with the rhodium catalyst for the amperometric detection of hydrogen peroxide in different concentrations of methanol, isopropanol and ethanol is demonstrated.

  • 34.
    Macken, Stephen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Di Natale, Corrado
    University Roma Tor Vergata, Italy.
    Paolesse, Roberto
    University Roma Tor Vergata, Italy.
    DAmico, Arnaldo
    University Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Towards integrated devices for computer screen photo-assisted multi-parameter sensing2009In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 632, no 1, 143-147 p.Article in journal (Refereed)
    Abstract [en]

    The computer screen photo-assisted technique (CSPT) utilizes consumer electronic devices such as computer screens and web cameras for distributed chemical sensing. Key to this method is the development of small and disposable sensing assays able to aid the CSPT optical detection, and the evaluation of multiple indicators. Here we demonstrate CSPT identification of fluorescent indicators from individual 100 mu m SU-8 (10) pillars covering an area of 4 mm x 4 mm with a density of 47 elements mm-2. The extraction of distinctive spectral fingerprints is aided by the exploitation of a three-band Moire interference that enables the partial Bayer decoding of the CSPT images.

  • 35.
    Mandenius, Carl-Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, The Institute of Technology.
    Wang, Ronghui
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Aldén, Anna
    School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar, Sweden.
    Bergström, Gunnar
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Thébault, Sabine
    Process Development Purification, Sanofi Pasteur, Campus Merieux 1541, Avenue Marcel Merieux, F-69280 Marcy l’ Etoile, France.
    Lutsch, Charles
    Process Development Purification, Sanofi Pasteur, Campus Merieux 1541, Avenue Marcel Merieux, F-69280 Marcy l’ Etoile, France.
    Ohlson, Sten
    School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar, Sweden.
    Monitoring of influenza virus hemagglutinin in process samples using weak affinity ligands and surface plasmon resonance2008In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 623, 66-75 p.Article in journal (Refereed)
    Abstract [en]

    Surface plasmon resonance (SPR) was used to screen the interaction between a variety of affinity ligands and hemagglutinin (HA) from human influenza virus, with the aim of identifying low affinity ligands useful for the development of a rapid bioanalytical sensor. Three sialic acid-based structures and four lectins were evaluated as sensor ligands. The sialic acid-based ligands included a natural sialic acid-containing glycoprotein, human α1-acid glycoprotein (α1-AGP), and two synthetic 6′-sialyllactose-conjugates, with varying degree of substitution. The interaction of HA with the four lectin-based ligands, concanavalin A (Con A), wheat germ agglutinin (WGA), Maackia amurensis lectin (MAL), and Sambucus nigra agglutinin (SNA), showed a wide variation of affinity strengths. Affinity and kinetics data were estimated. Strong affinities were observed for Con A, WGA, α1-AGP, and a 6′-sialyllactose-conjugate with a high substitution degree, and low affinities were observed for MAL and a 6′-sialyllactose-conjugate with low substitution.

    The main objective, to identify a low affinity ligand which could be used for on-line monitoring and product quantification, was met by a 6′-sialyllactose–ovalbumin conjugate that had 0.6 mol ligand per mol carrier protein. The apparent affinity of this ligand was estimated to be 1.5 ± 0.03 μM (KD) on the SPR surface. Vaccine process samples containing HA were analyzed in the range 10–100 μg HA mL−1 and correlated with single-radial immunodiffusion. The coefficient of variation on the same chip was between 0.010 and 0.091.

  • 36. Markowski, Piotr
    et al.
    Baranowska, Irena
    Baranowski, Jacek
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Simultaneous determination of l-arginine and 12 molecules participating in its metabolic cycle by gradient RP-HPLC method. Application to human urine samples2007In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 605, no 2, 205-217 p.Article in journal (Refereed)
    Abstract [en]

    We have developed and described a highly sensitive, accurate and precise reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of l-arginine and 12 molecules participating in its metabolic cycle in human urine samples. After pre-column derivatization with ortho-phthaldialdehyde (OPA) reagent containing 3-mercaptopropionic acid (3MPA), the fluorescent derivatives were separated by a gradient elution and detected by fluorescence measurement at 338 nm (excitation) and 455 nm (emission). l-Arginine (ARG) and its metabolites: l-glutamine (GLN), NG-hydroxy-l-arginine (NOHA), l-citrulline (CIT), NG-monomethyl-l-arginine (NMMA), l-homoarginine (HARG), asymmetric NG,NG-dimethyl-l-arginine (ADMA), symmetric NG,NG′-dimethyl-l-arginine (SDMA), l-ornithine (ORN), putrescine (PUT), agmatine (AGM), spermidine (SPERMD) and spermine (SPERM) were extracted in a cation-exchange solid-phase extraction (SPE) column and after derivatization separated in a Purospher® STAR RP-18e analytical column. The calibration curves of analysed compounds are linear within the range of concentration: 45-825, 0.2-15, 16-225, 12-285, 0.1-32, 15-235, 0.1-12, 0.1-12, 10-205, 0.02-12, 0.1-24, 0.01-10 and 0.01-8 nmol mL-1 for GLN, NOHA, CIT, ARG, NMMA, HARG, ADMA, SDMA, ORN, PUT, AGM, SPERMD and SPERM, respectively. The correlation coefficients are greater than 0.9980. Coefficients of variation are not higher than 6.0% for inter-day precision. The method has been determined or tested for limits of detection and quantification, linearity, precision, accuracy and recovery. All detection parameters of the method demonstrate that it is a reliable and efficient means of the comprehensive determination of ARG and its 12 main metabolites, making this approach suitable for routine clinical applications. The levels of analysed compounds in human urine can be successfully determined using this developed method with no matrix effect. © 2007 Elsevier B.V. All rights reserved.

  • 37.
    Mecklenburg, M.
    et al.
    Pure and Applied Biochemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
    Svitel, J.
    Pure and Applied Biochemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Gang, J.
    Ornstein, K.
    Department of Infectious Diseases, Lund University Hospital, SE-22185 Lund, Sweden.
    Dey, E.
    Pure and Applied Biochemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
    Bin, X.
    Pure and Applied Biochemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
    Hedborg, E.
    Norrby, R.
    Department of Infectious Diseases, Lund University Hospital, SE-22185 Lund, Sweden.
    Arwin, H.
    Department of Infectious Diseases, Lund University Hospital, SE-22185 Lund, Sweden.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Danielsson, B.
    Pure and Applied Biochemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
    Differentiation of human serum samples by surface plasmon resonance monitoring of the integral glycoprotein interaction with a lectin panel2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 459, no 1, 25-31 p.Article in journal (Refereed)
    Abstract [en]

    Bacterial infection and inflammation result in massive changes in serum glycoproteins. These changes were investigated by the interaction of the saccharide glycoprotein moiety with lectins. A panel of eight lectins (Canavalia ensiformis, Bandeiraea simplicifolia BS-I, Arachis hypogaea, Phytolacca americana, Phaseolus vulgaris, Artocarpus integrifolia, Triticum vulgaris and Pisum sativum) was used to differentiate human serum glycoproteins obtained from patients with various bacterial infections. Lectin functionalised sensing layers were created on gold-coated wafers and lectin-glycoprotein interactions were monitored by surface plasmon resonance. The interaction of the lectin panel with serum glycoproteins produces unique patterns. Principal component analysis (PCA) was used to analyse the patterns. The actual panel of eight lectins enabled discrimination between sera obtained from patients sick with bacterial infection and healthy patients. Extended lectin panels have the potential to distinguish between types of bacterial infection and identify specific disease state. © 2002 Elsevier Science B.V. All rights reserved.

  • 38.
    NEWMAN, JD
    et al.
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; UNIV FLORENCE,DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALYT AMBIENTALE,I-50121 FLORENCE,ITALY; .
    TURNER, APF
    Cranfield University, UK.
    MARRAZZA, G
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; UNIV FLORENCE,DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALYT AMBIENTALE,I-50121 FLORENCE,ITALY; .
    INK-JET PRINTING FOR THE FABRICATION OF AMPEROMETRIC GLUCOSE BIOSENSORS1992In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 262, no 1, 13-17 p.Article in journal (Refereed)
    Abstract [en]

    Ink-jet printing has been demonstrated as a manufacturing technique that facilitates the rapid, reproducible and economical production of amperometric glucose biosensors. Glucose was chosen as the analyte for demonstrating the process. For eight electrodes produced, the relative standard deviation of the response was less than 5%. The technique is extremely versatile, and will enable a wide variety of reagents to be placed on virtually any sensor design. This technique will be of particular benefit for the mass manufacture of intricate devices, where existing production techniques, such as screen-printing, may not be suitable.

  • 39.
    Palchetti, I
    et al.
    UNIV FLORENCE, DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALIT, I-50121 FLORENCE, ITALY; CRANFIELD UNIV, CRANFIELD BIOTECHNOL CTR, CRANFIELD MK43 0AL, BEDS, ENGLAND; ARPAT, DIPARTIMENTO PROV PISTOIA, PISTOIA, ITALY; .
    Cagnini, A
    UNIV FLORENCE, DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALIT, I-50121 FLORENCE, ITALY; CRANFIELD UNIV, CRANFIELD BIOTECHNOL CTR, CRANFIELD MK43 0AL, BEDS, ENGLAND; ARPAT, DIPARTIMENTO PROV PISTOIA, PISTOIA, ITALY; .
    DelCarlo, M
    UNIV FLORENCE, DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALIT, I-50121 FLORENCE, ITALY; CRANFIELD UNIV, CRANFIELD BIOTECHNOL CTR, CRANFIELD MK43 0AL, BEDS, ENGLAND; ARPAT, DIPARTIMENTO PROV PISTOIA, PISTOIA, ITALY; .
    Coppi, C
    UNIV FLORENCE, DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALIT, I-50121 FLORENCE, ITALY; CRANFIELD UNIV, CRANFIELD BIOTECHNOL CTR, CRANFIELD MK43 0AL, BEDS, ENGLAND; ARPAT, DIPARTIMENTO PROV PISTOIA, PISTOIA, ITALY; .
    Mascini, M
    UNIV FLORENCE, DIPARTIMENTO SANITA PUBBL EPIDEMIOL and CHIM ANALIT, I-50121 FLORENCE, ITALY; CRANFIELD UNIV, CRANFIELD BIOTECHNOL CTR, CRANFIELD MK43 0AL, BEDS, ENGLAND; ARPAT, DIPARTIMENTO PROV PISTOIA, PISTOIA, ITALY; .
    Turner, APF
    Cranfield University, UK.
    Determination of anticholinesterase pesticides in real samples using a disposable biosensor1997In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 337, no 3, 315-321 p.Article in journal (Refereed)
    Abstract [en]

    A choline amperometric biosensor based on screen-printed electrodes was assembled and used to assess the inhibitory effect of organophosphorus and carbamic pesticides on acetylcholinesterase activity both in standard solutions and real samples, Acetylcholinesterase catalyses the cleavage of acetylcholine to choline and acetate, therefore the amount of choline measured using the biosensor is directly related to the enzyme activity. The extent of enzyme inhibition can be used as an index of the amount of anticholinesterase pesticides present. The hydrophobicity of organophosphorus and carbamic pesticides led to the evaluation of organic, water miscible solvents for use in the proposed method. Berate buffer containing 1% v/v acetonitrile was selected since it exhibited the least influence on enzyme activity from the tested solvents (acetonitrile, acetone, tetrahydrofuran and ethylacetate). Other solvents (dimethylsulfoxide and methanol) were avoided as they exhibited electrochemical interferences. An inhibition calibration curve was obtained using carbofuran, a strong inhibitor of acetylcholinesterase. The lowest detectable standard solution (mean +/-3 standard deviation of the blank) was 2 mu gl(-1) following an incubation time of 10 min. The method was then applied to real samples (fruits and vegetables) showing its suitability as a rapid screening assay (12 min per test) for the assessment of anticholinesterase pesticides, The biosensor results were compared with a standard analytical technique (gas chromatography with nitrogen phosphorus detector, GC-NPD).

  • 40.
    Palleschi, G.
    et al.
    Cranfield Institute of Technology, Biotechnology Centre, Cranfield, Bedford , UK.
    Turner, Anthony P. F.
    Cranfield University, UK.
    Amperometric tetrathiafulvalene-mediated lactate electrode using lactate oxidase absorbed on carbon foil1990In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 234, no 2, 459-463 p.Article in journal (Other academic)
    Abstract [en]

    The features of a new sensor for determining l-lactate are reported. The enzyme lactate oxidase and the mediator, tetrathiafulvalene (TTF), are absorbed on carbon foil disks previously bonded onto the ends of glass tubes. Linear calibration graphs were obtained in the range 10−4−10−3 M with physiological phosphate buffer (pH 7.35) and at 30°C with a response time of a few seconds. Calibration graphs in the range 10−3−10−2 M were also obtained and the difference in response times between these two ranges were investigated. The results are promising for assembling disposable lactate sensors for in vitro or for in or ex vivo measurements.

  • 41.
    Piletska, Elena V.
    et al.
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Piletsky, Sergey
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Karim, Kal
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Terpetschnig, Ewald
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Turner, Anthony
    Cranfield University, UK.
    Biotin-specific synthetic receptors prepared using molecular imprinting2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 504, no 1, 179-183 p.Article in journal (Refereed)
    Abstract [en]

    The composition of new molecularly imprinted polymers (MIPs) specific for biotin was optimised using molecular modelling software. Three functional monomers: methacrylic acid (MAA), 2-(trifluoromethyl)acrylic acid (TFAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPSA), which demonstrated the highest binding scores with biotin, were tested on their ability to generate specific binding sites. The imprinted polymers were photografted to the surface of polystyrene microspheres in water. The affinity of the synthetic "receptor" sites was evaluated in binding experiments using horseradish peroxidase-labelled biotin. Good correlation was found between the modelling results and the performance of the materials in the template re-binding study. The dissociation constants for all MIPs were 1.4-16.8 nM, which is sufficient for most analytical applications where biotin is used as a label.

  • 42.
    Piletska, Elena V.
    et al.
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Romero-Guerra, Maria
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Chianella, Iva
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Karim, Kal
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Turner, Anthony P.F.
    Cranfield University, UK.
    Piletsky, Sergey A.
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Towards the development of multisensor for drugs of abuse based on molecular imprinted polymers2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 542, no 1, 111-117 p.Article in journal (Refereed)
    Abstract [en]

    The synthetic receptors for cocaine, deoxyephedrine, methadone and morphine were computationally designed and produced using molecular imprinting. The structure and energy of the molecular complexes were analysed by computational techniques. The possible structures of the binding sites in the synthetic receptors have been compared with those of corresponding natural receptors. The composition of imprinted polymers was optimised to allow adequate performance under the same experimental conditions. All selected molecular imprinting polymers (MIPs) demonstrated stronger affinity in comparison with corresponding blank polymers resulting in imprinted factors (1) equal to 1.2 (cocaine), 2.5 (deoxyephedrine), 3.5 (methadone) and 3 (morphine) which suggested that the specific binding site for each molecule was successfully created. The polymers studied possessed good selectivity and affinity towards their templates and could be recommended for the integration with sensor devices. From a practical point of view, especially for multisensor requirements, the synthetic receptors based on imprinted polymers could be superior to natural receptors due to their stability, robustness and compatibility with automation processes required for sensor fabrication.

  • 43.
    Piletska, EV
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Romero-Guerra, M
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Guerreiro, AR
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Piletsky, SA
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Adaptation of the molecular imprinted polymers towards polar environment2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 542, no 1, 47-51 p.Article in journal (Refereed)
    Abstract [en]

    A new simple method for the post-polymerisation treatment of molecularly imprinted polymers was proposed. A layer of mineral oil was deposited onto the surface of the polymer in order to create a hydrophobic environment in the binding sites and to improve the recognition properties of the polymer in polar solvents. The testing of polymers performed in acetonitrile showed that the modified polymers possessed significantly increased selectivity as compared with non-treated ones. The three-fold improvement of recognition of the template (cocaine) was achieved; the same time, for non-specific molecule (morphine) the improvement was only 1.3 times. The investigation of the stability of mineral oil coating on the polymer surface suggested that the effect produced is stable over a long period of time. This approach could be used to broaden the range of experimental conditions where molecularly imprinted polymers can perform successfully. (c) 2005 Elsevier B.V. All rights reserved.

  • 44.
    Piletsky, Sergey
    et al.
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Piletska, Elena
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Karim, Kal
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Foster, Graham
    GlaxoSmithKline Research and Development, Stevenage, Herts, UK.
    Legge, Colton
    GlaxoSmithKline Research and Development, Stevenage, Herts, UK.
    Turner, Anthony
    Cranfield University, UK.
    Custom synthesis of molecular imprinted polymers for biotechnological application - Preparation of a polymer selective for tylosin2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 504, no 1, 123-130 p.Article in journal (Refereed)
    Abstract [en]

    A molecularly imprinted polymer (MIP) selective for tylosin was designed and synthesised using a computational method (MIP "dialling"). In re-binding experiments the MIP demonstrated high affinity for tylosin in aqueous solutions and in organic solvents. The synthesised polymer was tested for re-binding with the template and related metabolites such as tylactone, narbomycin and picromycin. The HPLC analysis showed that the computationally designed polymer is specific and capable of separating the template from its structural analogues. The MIP was capable of recovering tylosin from broth samples. The polymer capacity for tylosin was estimated as 6.4 mg/g for MIP, which was suitable for practical application and tylosin recovery from broth samples. Among the advantages of this was the possibility to adsorb tylosin from a complex media with easy removal of oils and other impurities which are present in significant quantities, which can create problems for its chromatographic purification procedure. The MIP "dialling" procedure can have a general significance for the fast preparation of specific adsorbents for biotechnological applications.

  • 45.
    RAMSAY, G
    et al.
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    DEVELOPMENT OF AN ELECTROCHEMICAL METHOD FOR THE RAPID-DETERMINATION OF MICROBIAL CONCENTRATION AND EVIDENCE FOR THE REACTION-MECHANISM1988In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 215, no 02-jan, 61-69 p.Article in journal (Refereed)
    Abstract [en]

    n/a

  • 46.
    SAINI, S
    et al.
    CRANFIELD BIOTECHNOL LTD,CRANFIELD MK43 0AL,BEDS,ENGLAND; LAB GOVT CHEMIST,SENSORS TECHNOL GRP,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    HALL, GF
    CRANFIELD BIOTECHNOL LTD,CRANFIELD MK43 0AL,BEDS,ENGLAND; LAB GOVT CHEMIST,SENSORS TECHNOL GRP,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    DOWNS, MEA
    CRANFIELD BIOTECHNOL LTD,CRANFIELD MK43 0AL,BEDS,ENGLAND; LAB GOVT CHEMIST,SENSORS TECHNOL GRP,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    ORGANIC-PHASE ENZYME ELECTRODES1991In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 249, no 1Article in journal (Refereed)
    Abstract [en]

    Organic phase enzyme electrodes (OPEEs) offer new possibilities both for the design of biosensors for use in organic solvents and in the construction of devices incorporating an organic phase for use with aqueous samples. The advantages that accrue from performing biocatalytic and electrochemical reactions in non-aqueous systems are discussed in relation to possible applications in medicine. pharmaceuticals, petrochemicals, the food industry, environmental monitoring and defence. This critical but speculative review considers the detailed implications of operating enzyme electrodes in organic solvents and briefly examines the broader issues of optical, calorimetric and piezoelectric transduction coupled with both catalytic and affinity systems, such as nucleic acid probes and antibodies.

  • 47.
    Schmekel, Birgitta
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Vikström, Anders
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Respiratory Medicine.
    Analysis of breath samples for lung cancer survival2014In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 840, 82-86 p.Article in journal (Refereed)
    Abstract [en]

    Analyses of exhaled air by means of electronic noses offer a large diagnostic potential. Such analyses are non-invasive; samples can also be easily obtained from severely ill patients and repeated within short intervals. Lung cancer is the most deadly malignant tumor worldwide, and monitoring of lung cancer progression is of great importance and may help to decide best therapy. In this report, twenty-two patients with diagnosed lung cancer and ten healthy volunteers were studied using breath samples collected several times at certain intervals and analysed by an electronic nose. The samples were divided into three sub-groups; group d for survivor less than one year, group s for survivor more than a year and group h for the healthy volunteers. Prediction models based on partial least square and artificial neural nets could not classify the collected groups d, s and h, but separated well group d from group h. Using artificial neural net, group d could be separated from group s. Excellent predictions and stable models of survival day for group d were obtained, both based on partial least square and artificial neural nets, with correlation coefficients 0.981 and 0.985, respectively. Finally, the importance of consecutive measurements was shown.

  • 48.
    SCHUBERT, F
    et al.
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    SAINI, S
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    MEDIATED AMPEROMETRIC ENZYME ELECTRODE INCORPORATING PEROXIDASE FOR THE DETERMINATION OF HYDROGEN-PEROXIDE IN ORGANIC-SOLVENTS1991In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 245, no 2, 133-138 p.Article in journal (Refereed)
    Abstract [en]

    An amperometric enzyme electrode incorporating horseradish peroxidase is described for the determination of hydrogen peroxide in organic solvents. The enzyme was co-adsorbed with an electron mediator, potassium hexacyanoferrate(II), on the surface of a graphite foil electrode, making reagentless measurement possible. The electrochemical reduction of the enzymatically oxidized mediator was utilized as the analytical signal. Studies in different solvent systems revealed that the electrode could be operated in dioxane, chloroform and chlorobenzene, the last two providing approximately double the sensitivity of the former. The presence of a small amount of aqueous buffer was essential for sensor activity. During 2 weeks of intermittent use, the sensitivity of the electrode decreased to 40% of its initial value. At least 50 assays could be performed with a single sensor.

  • 49.
    Sekretaryova, Alina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Volkov, Anton V.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Zozoulenko, Igor V.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Vagin, Mikhail Yu
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Total phenol analysis of weakly supported water using a laccase-based microband biosensor.2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 907, 45-53 p.Article in journal (Refereed)
    Abstract [en]

    The monitoring of phenolic compounds in wastewaters in a simple manner is of great importance for environmental control. Here, a novel screen printed laccase-based microband array for in situ, total phenol estimation in wastewaters and for water quality monitoring without additional sample pre-treatment is presented. Numerical simulations using the finite element method were utilized for the characterization of micro-scale graphite electrodes. Anodization followed by covalent modification was used for the electrode functionalization with laccase. The functionalization efficiency and the electrochemical performance in direct and catechol-mediated oxygen reduction were studied at the microband laccase electrodes and compared with macro-scale electrode structures. The reduction of the dimensions of the enzyme biosensor, when used under optimized conditions, led to a significant improvement in its analytical characteristics. The elaborated microsensor showed fast responses towards catechol additions to tap water – a weakly supported medium – characterized by a linear range from 0.2 to 10 μM, a sensitivity of 1.35 ± 0.4 A M−1 cm−2 and a dynamic range up to 43 μM. This enhanced laccase-based microsensor was used for water quality monitoring and its performance for total phenol analysis of wastewater samples from different stages of the cleaning process was compared to a standard method.

  • 50.
    Tang, AXJ
    et al.
    Natl University Ireland University Coll Cork, Department Chemistry, Cork, Ireland; Cranfield University, Bedford MK45 4DT, England; .
    Pravda, M
    Natl University Ireland University Coll Cork, Department Chemistry, Cork, Ireland; Cranfield University, Bedford MK45 4DT, England; .
    Guilbault, GG
    Natl University Ireland University Coll Cork, Department Chemistry, Cork, Ireland; Cranfield University, Bedford MK45 4DT, England; .
    Piletsky, S
    Natl University Ireland University Coll Cork, Department Chemistry, Cork, Ireland; Cranfield University, Bedford MK45 4DT, England; .
    Turner, APF
    Cranfield University, UK.
    Immunosensor for okadaic acid using quartz crystal microbalance2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 471, no 1, 33-40 p.Article in journal (Refereed)
    Abstract [en]

    An immunosensor for the determination of okadaic acid (OA) using a quartz crystal microbalance (QCM) was developed and optimised in standard solutions. Several coupling techniques, protein A, protein G and polyethylenimine (PEI) with glutaraldehyde (GA) cross-linking, were investigated for the determination of okadaic acid and a very good result was obtained with PEI coupling. With the PEI coupling method, the optimisation of incubation time for the activation of PEI on the crystal surface using GA, the effect of the dilution factor of OA-bovine serum albumin (BSA) conjugate and the amount of antibody on crystal frequency were studied. Different molar ratios (4:1, 14:1, 30:1) of OA to bovine serum albumin for the conjugation were examined and the results using ELISA and a QCM showed that a ratio of 14:1 was slightly better than the other two. The strong attachment of the cross-linked complex to the gold surface resulted in an excellent storage lifetime of 38 days. However, the detection limit (1.9 mug/ml) and the sensitivity of the sensor were not satisfactory. Significant improvement of the performance of the device was obtained by incorporating an antibody-BSA hydrogel. Initial results showed that the minimum amount of analyte detectable and the sensitivity of the device were improved by 524- and 80-fold, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.

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