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Ali, S.U.
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Publications (10 of 29) Show all publications
Usman Ali, S., Ibupoto, Z. H., Kashif, M., Hashim, U. & Willander, M. (2012). A Potentiometric Indirect Uric Acid Sensor Based on ZnO Nanoflakes and Immobilized Uricase. Sensors, 12(3), 2787-2797
Open this publication in new window or tab >>A Potentiometric Indirect Uric Acid Sensor Based on ZnO Nanoflakes and Immobilized Uricase
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2012 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 12, no 3, p. 2787-2797Article in journal (Refereed) Published
Abstract [en]

In the present work zinc oxide nanoflakes (ZnO-NF) structures with a wall thickness around 50 to 100 nm were synthesized on a gold coated glass substrate using a low temperature hydrothermal method. The enzyme uricase was electrostatically immobilized in conjunction with Nafion membrane on the surface of well oriented ZnO-NFs, resulting in a sensitive, selective, stable and reproducible uric acid sensor. The electrochemical response of the ZnO-NF-based sensor vs. a Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (500 nM to 1.5 mM). In addition, the ZnO-NF structures demonstrate vast surface area that allow high enzyme loading which results provided a higher sensitivity. The proposed ZnO-NF array-based sensor exhibited a high sensitivity of similar to 66 mV/ decade in test electrolyte solutions of uric acid, with fast response time. The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea.

Place, publisher, year, edition, pages
MDPI, 2012
Keywords
ZnO nanoflakes (ZnO-NFs), potentiometric nanosensor, uricase, Nafion (R) membrane
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-76956 (URN)10.3390/s120302787 (DOI)000302125000023 ()
Available from: 2012-05-02 Created: 2012-04-27 Last updated: 2017-08-30
Kashif, M., Al-Douri, Y., Hashim, U., Ali, M. E., Usman Ali, S. & Willander, M. (2012). Characterisation, analysis and optical properties of nanostructure ZnO using the sol-gel method. Micro & Nano Letters, 7(2), 163-167
Open this publication in new window or tab >>Characterisation, analysis and optical properties of nanostructure ZnO using the sol-gel method
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2012 (English)In: Micro & Nano Letters, ISSN 1750-0443, E-ISSN 1750-0443, Vol. 7, no 2, p. 163-167Article in journal (Refereed) Published
Abstract [en]

Nanostructure ZnO was grown on thin aluminium layer, deposited on silicon substrate using the sol-gel method. The surface morphologies of nanostructure ZnO at different precursor concentrations were studied using scanning electron microscopy. Raman spectroscopy suggested that nanorods started to grow along with nanoflakes at a precursor concentration of 50 mM and the density of the nanorods significantly increases when the concentration was raised to 75 mM. Raman spectra were intensified and red shifted with the increment of precursor concentration. Optical properties of refractive index and optical dielectric constant are investigated. The structural defects at lower level of precursor were probably due to the hypoxic environment, whereas the red shift of Raman spectra was due to the structural change of ZnO nanocrystals.

Place, publisher, year, edition, pages
Institution of Engineering and Technology (IET), 2012
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-75903 (URN)10.1049/mnl.2011.0681 (DOI)000300623000018 ()
Note

Funding Agencies|FRGS|9003-002499003-00255|

Available from: 2012-03-16 Created: 2012-03-16 Last updated: 2017-12-07
Ibupoto, Z. H., Usman Ali, S., Khun, K. & Willander, M. (2012). Electrochemical L-Lactic Acid Sensor Based on Immobilized ZnO Nanorods with Lactate Oxidase. Sensors, 12(3), 2456-2466
Open this publication in new window or tab >>Electrochemical L-Lactic Acid Sensor Based on Immobilized ZnO Nanorods with Lactate Oxidase
2012 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 12, no 3, p. 2456-2466Article in journal (Refereed) Published
Abstract [en]

In this work, fabrication of gold coated glass substrate, growth of ZnO nanorods and potentiometric response of lactic acid are explained. The biosensor was developed by immobilizing the lactate oxidase on the ZnO nanorods in combination with glutaraldehyde as a cross linker for lactate oxidase enzyme. The potentiometric technique was applied for the measuring the output (EMF) response of L-lactic acid biosensor. We noticed that the present biosensor has wide linear detection range of concentration from 1 x 10(-4)-1 x 10(0) mM with acceptable sensitivity about 41.33 +/- 1.58 mV/decade. In addition, the proposed biosensor showed fast response time less than 10 s, a good selectivity towards L-lactic acid in presence of common interfering substances such as ascorbic acid, urea, glucose, galactose, magnesium ions and calcium ions. The present biosensor based on immobilized ZnO nanorods with lactate oxidase sustained its stability for more than three weeks.

Place, publisher, year, edition, pages
MDPI, 2012
Keywords
zinc oxide nanorods, lactate oxidase enzyme, glutaraldehyde, potentiometric nanostructured biosensor, nanodevices
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-76959 (URN)10.3390/s120302456 (DOI)000302125000006 ()
Available from: 2012-05-02 Created: 2012-04-27 Last updated: 2017-08-30
Fakhar-e-Alam, M., Usman Ali, S., Ibupoto, Z. H., Atif, M. & Willander, M. (2012). Erratum: “Phototoxic Effects of Zinc Oxide Nanowires (ZnO NWs) Complexed with 5-ALA in RD Cell Line” (Laser Physics 21, 2165 (2011)). Laser physics, 22(1), 338-338
Open this publication in new window or tab >>Erratum: “Phototoxic Effects of Zinc Oxide Nanowires (ZnO NWs) Complexed with 5-ALA in RD Cell Line” (Laser Physics 21, 2165 (2011))
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2012 (English)In: Laser physics, ISSN 1054-660X, E-ISSN 1555-6611, Vol. 22, no 1, p. 338-338Article in journal (Other academic) Published
Abstract [en]

n/a

Place, publisher, year, edition, pages
MAIK Nauka/Interperiodica, 2012
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-74853 (URN)10.1134/S1054660X12010331 (DOI)000298994000056 ()
Available from: 2012-02-10 Created: 2012-02-10 Last updated: 2017-08-30
Fakhar-e-Alam, M., Usman Ali, S., Hussain Ibupoto, Z., Atif, M. & Willander, M. (2012). Erratum: “Phototoxic effects of zinc oxide nanowires (ZnO NWs) complexed with 5-ALA in RD cell line” (Laser Physics 21, 2165 (2011)). Laser physics, 22(2), 476-476
Open this publication in new window or tab >>Erratum: “Phototoxic effects of zinc oxide nanowires (ZnO NWs) complexed with 5-ALA in RD cell line” (Laser Physics 21, 2165 (2011))
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2012 (English)In: Laser physics, ISSN 1054-660X, E-ISSN 1555-6611, Vol. 22, no 2, p. 476-476Article in journal (Other academic) Published
Abstract [en]

n/a

Place, publisher, year, edition, pages
M A I K Nauka - Interperiodica, 2012
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-76023 (URN)10.1134/S1054660X12020326 (DOI)000300671700032 ()
Available from: 2012-03-29 Created: 2012-03-23 Last updated: 2017-08-30
Ali, S. M. U. (2012). Fabrication and characterization of ZnO nanostructures for sensing and photonic device applications. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Fabrication and characterization of ZnO nanostructures for sensing and photonic device applications
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanotechnology is an emerging inter-disciplinary paradigm which encompasses diverse fields of science and engineering converge at the nanoscale. This nanoscale science and nanostructure engineering have well demonstrated in the fabrication of sensors/transducers devices with faster response time and better sensitivity then the planer version of the sensor’s configurations. Nanotechnology is not just to grow/fabricate nanostructures by just mixing nanoscale materials together but it requires the ability to understand and to precisely manipulate and control of the developed nanomaterials in a useful way. Nanotechnology is aiding to substantially improve, even revolutionize, many technology and industry sectors like information technology, energy, environmental science, medicine/medical instrumentation, homeland security, food safety, and transportation, among many others. Such applications of nanotechnology are delivering in both expected and unexpected ways on nanotechnology’s promise to benefit the society.

The semiconductor ZnO with wide band gap (~ 3.37 eV) is a distinguish and unique material and its nanostructures have attracted great attention among the researchers due to its peculiar properties such as large exciton binding energy (60 meV) at room temperature, the high electron mobility, high thermal conductivity, good transparency and easiness of fabricating it in the different type of nanostructures. Based on all these fascinating properties, ZnO have been chosen as a suitable material for the fabrication of photonic, transducers/sensors, piezoelectric, transparent and spin electronics devices etc. The objective of the current study is to highlight the recent developments in materials and techniques for electrochemical sensing and hetrostructure light emitting diodes (LEDs) luminescence properties based on the different ZnO nanostructures. The sensor devices fabricated and characterized in the work were applied to determine and monitor the real changes of the chemical or biochemical species. We have successfully demonstrated the application of our fabricated devices as primary transducers/sensors for the determination of extracellular glucose and the glucose inside the human fat cells and frog cells using the potentiometric technique. Moreover, the fabricated ZnO based nanosensors have also been applied for the selective determination of uric acid, urea and metal ions successfully. This thesis relates specifically to zinc oxide nanostructure based electrochemical sensors and photonic device (LED) applications.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2012. p. 76
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1412
Keywords
Nanotechnology, zinc oxide, nanowires/ nanorods, nanotubes, nanoporous/nanoflakes, electrochemical sensor and photonic devices
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-72774 (URN)978-91-7393-015-4 (ISBN)
Public defence
2012-01-17, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:15 (English)
Opponent
Supervisors
Available from: 2011-12-07 Created: 2011-12-07 Last updated: 2014-01-15Bibliographically approved
Khun, K., Ibupoto, Z. H., Usman Ali, S., Ouern Chey, C., Nur, O. & Willander, M. (2012). Iron Ion Sensor Based on Functionalized ZnO Nanorods. Electroanalysis, 24(3), 521-528
Open this publication in new window or tab >>Iron Ion Sensor Based on Functionalized ZnO Nanorods
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2012 (English)In: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 24, no 3, p. 521-528Article in journal (Refereed) Published
Abstract [en]

In this work, we are presenting an iron ion (Fe3+) potentiometric sensor based on functionalized ZnO nanorods with selective ionophore (18 crown 6). Zinc oxide nanorods with a diameter of about 100 to 150 nm and 1 mu m in length were grown on gold coated glass. The selective Fe3+ ionophore sensor with highly aligned ZnO nanorods showed high sensitivity, acceptable selectivity, reproducibility and a stable signal response for detecting Fe3+. The potentiometric response of the Fe3+ sensor with functionalized ZnO nanorods versus a Ag/AgCl reference electrode was observed to be linear over a logarithmic concentration range from 10-5 M to 10-2 M. The detection limit of the proposed sensor was about 5 mu M, which is lower than the normal blood concentration of Fe3+ which is about 10 mu M and can be up to 30 +/- M. The sensitivity of the proposed Fe3+ sensor was found to be 70.2 +/- 2.81 mV/decade with a regression coefficient R2=0.99 and a response time less than 5 s. The functionalized ZnO nanorods sensor with selective iron ionophore has a life time greater than one month and has shown insignificant interference with other ions usually present in the human blood serum. The proposed sensor was used as an indicator electrode for potentiometric titration.

Place, publisher, year, edition, pages
Wiley-VCH Verlag Berlin, 2012
Keywords
Immobilization, Ionophore (18 crown 6), Potentiometric chemical sensors, ZnO nanorods
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-76018 (URN)10.1002/elan.201100494 (DOI)000300931000009 ()
Note

Funding Agencies|Uppsala University, Sweden||Royal University of Phnom Penh (RUPP), Cambodia||

Available from: 2012-03-29 Created: 2012-03-23 Last updated: 2017-08-30
Kashif, M., Usman Ali, S., Ali, M., Abdulgafour, H., Hashim, U., Willander, M. & Hassan, Z. (2012). Morphological, optical, and Raman characteristics of ZnO nanoflakes prepared via a sol-gel method. PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 209(1), 143-147
Open this publication in new window or tab >>Morphological, optical, and Raman characteristics of ZnO nanoflakes prepared via a sol-gel method
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2012 (English)In: PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, ISSN 1862-6300, Vol. 209, no 1, p. 143-147Article in journal (Refereed) Published
Abstract [en]

Two-dimensional (2D) ZnO nanoflakes were grown on thin aluminum layer, deposited on silicon substrate, using a sol-gel method. The surface morphologies of ZnO nanoflakes at different precursor concentrations were studied using scanning electron microscopy (SEM). Combined studies of SEM, photoluminescence (PL), and Raman spectroscopy suggested that nanorods started to grow along with nanoflakes at a precursor concentration of 0.05 M and the density of the nanorods significantly increased when the concentration was raised to 0.075 M. Both the UV-luminescence and Raman spectra were intensified and redshifted with the increment of precursor concentration. Spectral intensification suggests improvement in crystal qualities and better optical properties of the fabricated ZnO nanostructures. The structural defects at lower levels of precursor were probably due to the hypoxic environment, whereas, the redshift of PL and Raman spectra was due to the local heating of ZnO nanocrystals.

Place, publisher, year, edition, pages
Wiley-VCH Verlag Berlin, 2012
Keywords
phonon redshift; precursor and seed solution; sol-gel; ZnO nanoflakes structures
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-86569 (URN)10.1002/pssa.201127357 (DOI)000303380700029 ()
Available from: 2012-12-19 Created: 2012-12-19 Last updated: 2014-01-15
Chey, C. O., Usman Ali, S. M., Ibupoto, Z. H., Khun, K., Nur, O. & Willander, M. (2012). Potentiometric creatinine biosensor based on ZnO nanowires. Journal of Nanoscience Letters, 2(4), 24-24
Open this publication in new window or tab >>Potentiometric creatinine biosensor based on ZnO nanowires
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2012 (English)In: Journal of Nanoscience Letters, ISSN 2231-4008, Vol. 2, no 4, p. 24-24Article in journal (Refereed) Published
Abstract [en]

In the present work, we have grown well-aligned zinc oxide (ZnO) nanowires (NWs) on the surface of gold coated glass substrates by a low temperature aqueous chemical growth (ACG) approach and utilized it as a potentiometric creatinine biosensor. This was achieved by electrostatic immobilization of creatinine deiminase (CD) on the surface of the ZnO NWs followed by applying a chitosan membrane in conjunction with glutaraldehyde. This immobilization resulted in a sensitive, selective, stable, reproducible and fast creatinine biosensor. The potentiometric response of the ZnO sensor vs. Ag/AgCl reference electrode was found to be linear over a wide logarithmic concentration of creatinine electrolyte solution ranging from 1-1000 µM. The sensor illustrates good linear sensitivity slope curve of ~33.9 mV/decade along with a rapid response time of ~7 s. Furthermore, the sensor response was unaffected by normal concentrations of common interferences such as potassium, calcium, magnesium, sodium, copper ions and glucose.

Place, publisher, year, edition, pages
Cognizure, 2012
Keywords
ZnO nanowires; Potentiometric nanosensor; Electrochemical nanodevices; Creatinine deiminase; Creatinine
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-112909 (URN)
Available from: 2014-12-19 Created: 2014-12-19 Last updated: 2015-01-13Bibliographically approved
Ibupoto, Z. H., Ali, S. M. U., Khun, K. & Willander, M. (2012). Selective Thallium (I) Ion Sensor Based on Functionalised ZnO Nanorods. Journal of Nanotechnology
Open this publication in new window or tab >>Selective Thallium (I) Ion Sensor Based on Functionalised ZnO Nanorods
2012 (English)In: Journal of Nanotechnology, ISSN 1687-9503Article in journal (Refereed) Published
Abstract [en]

Well controlled in length and highly aligned ZnO nanorods were grown on the gold-coated glass substrate by hydrothermal growth method. ZnO nanorods were functionalised with selective thallium (I) ion ionophore dibenzyldiaza-18-crown- 6 (DBzDA18C6). The thallium ion sensor showed wide linear potentiometric response to thallium (I) ion concentrations (1 × 10 - 7 M to 5 × 10 - 2 M) with high sensitivity of 36.87 ± 1.49 mV/decade. Moreover, thallium (I) ion demonstrated fast response time of less than 5 s, high selectivity, reproducibility, storage stability, and negligible response to common interferents. The proposed thallium (I) ion-sensor electrode was also used as an indicator electrode in the potentiometric titration, and it has shown good stoichiometric response for the determination of thallium (I) ion. © 2012 Z. H. Ibupoto et al.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2012
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87804 (URN)10.1155/2012/619062 (DOI)
Available from: 2013-01-31 Created: 2013-01-23 Last updated: 2014-09-10
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