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  • 701.
    Zhou, Yinhua
    et al.
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Zhang, Fengling
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Tvingstedt, Kristofer
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Barrau, Sophie
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Li, Fenghong
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Tian, Wenjing
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Investigation on Polymer Anode Design for Flexible Polymer Solar Cells2008Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 92Artikel i tidskrift (Refereegranskat)
    Abstract [en]

       

  • 702.
    Zhou, Yinhua
    et al.
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Zhang, Fengling
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Tvingstedt, Kristofer
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Tian, Wenjing
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Multifolded Polymer Solar Cells on Flexible Substrates2008Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 93, nr 033302Artikel i tidskrift (Refereegranskat)
  • 703.
    Zhou, Zichun
    et al.
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Xu, Shengjie
    Chinese Acad Sci, Peoples R China.
    Song, Jingnan
    Shanghai Jiao Tong Univ, Peoples R China.
    Jin, Yingzhi
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Yue, Qihui
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Qian, Yuhao
    Shanghai Jiao Tong Univ, Peoples R China.
    Liu, Feng
    Shanghai Jiao Tong Univ, Peoples R China.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Zhu, Xiaozhang
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    High-efficiency small-molecule ternary solar cells with a hierarchical morphology enabled by synergizing fullerene and non-fullerene acceptors2018Ingår i: NATURE ENERGY, ISSN 2058-7546, Vol. 3, nr 11, s. 952-959Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using combinatory photoactive blends is a promising approach to achieve high power conversion efficiency in ternary organic photovoltaics. However, the fundamental challenge of how to manipulate the morphology of multiple components and correlate structure details via device performance has not been well addressed. Achieving an ideal morphology that simultaneously enhances charge generation and transport and reduces voltage loss is an imperative avenue to improve device efficiency. Here, we achieve a high power conversion efficiency of 13.20 +/- 0.25% for ternary solar cells by using a combination of small molecules with both fullerene and non-fullerene acceptors, which form a hierarchical morphology consisting of a PCBM transporting highway and an intricate non-fullerene phase-separated pathway network. Carrier generation and transport find an optimized balance, and voltage loss is simultaneously reduced. Such a morphology fully utilizes the individual advantages of both fullerene and non-fullerene acceptors, demonstrating their indispensability in organic photovoltaics.

  • 704.
    Zhuang, Wenliu
    et al.
    Chalmers, Sweden .
    Zhen, Hongyu
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Kroon, Renee
    Chalmers, Sweden .
    Tang, Zheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hellstrom, Stefan
    Chalmers, Sweden .
    Hou, Lintao
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Wang, Ergang
    Chalmers, Sweden .
    Gedefaw, Desta
    Chalmers, Sweden .
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Andersson, Mats R.
    Chalmers, Sweden .
    Molecular orbital energy level modulation through incorporation of selenium and fluorine into conjugated polymers for organic photovoltaic cells2013Ingår i: JOURNAL OF MATERIALS CHEMISTRY A, ISSN 2050-7488, Vol. 1, nr 43, s. 13422-13425Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrated an effective chemical approach to modulate the energy levels of conjugated polymers by synergistically combining fluorine substitution and thiophene-selenophene exchange. Such modifications from TQ1 resulted in a significantly enhanced open-circuit voltage up to 1.0 V while retaining high photovoltaic performance.

  • 705.
    Zou, Wei
    et al.
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Li, Renzhi
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Zhang, Shuting
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Liu, Yunlong
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China; Liaocheng Univ, Peoples R China.
    Wang, Nana
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Cao, Yu
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Miao, Yanfeng
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Xu, Mengmeng
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Guo, Qiang
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Di, Dawei
    Univ Cambridge, England.
    Zhang, Li
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Yi, Chang
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Friend, Richard H.
    Univ Cambridge, England.
    Wang, Jianpu
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Huang, Wei
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China; Nanjing Univ Posts and Telecommun, Peoples R China; Nanjing Univ Posts and Telecommun, Peoples R China; Northwestern Polytech Univ, Peoples R China.
    Minimising efficiency roll-off in high-brightness perovskite light-emitting diodes2018Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikel-id 608Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efficiency roll-off is a major issue for most types of light-emitting diodes (LEDs), and its origins remain controversial. Here we present investigations of the efficiency roll-off in perovskite LEDs based on two-dimensional layered perovskites. By simultaneously measuring electroluminescence and photoluminescence on a working device, supported by transient photoluminescence decay measurements, we conclude that the efficiency roll-off in perovskite LEDs is mainly due to luminescence quenching which is likely caused by non-radiative Auger recombination. This detrimental effect can be suppressed by increasing the width of quantum wells, which can be easily realized in the layered perovskites by tuning the ratio of large and small organic cations in the precursor solution. This approach leads to the realization of a perovskite LED with a record external quantum efficiency of 12.7%, and the efficiency remains to be high, at approximately 10%, under a high current density of 500 mA cm(-2).

  • 706.
    Zou, Yatao
    et al.
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Ban, Muyang
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Yang, Yingguo
    Chinese Acad Sci, Peoples R China.
    Bai, Sai
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Wu, Chen
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Han, Yujie
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Wu, Tian
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Tan, Yeshu
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Huang, Qi
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Gao, Xingyu
    Chinese Acad Sci, Peoples R China.
    Song, Tao
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Zhang, Qiao
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Sun, Baoquan
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Boosting Perovskite Light-Emitting Diode Performance via Tailoring Interfacial Contact2018Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 28, s. 24320-24326Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Solution-processed perovskite light-emitting diodes (LEDs) have attracted wide attention in the past several years. However, the overall efficiency and stability of perovskite-based LEDs remain inferior to those of organic or quantum dot LEDs. Nonradiative charge recombination and the unbalanced charge injection are two critical factors that limit the device efficiency and operational stability of perovskite LEDs. Here, we develop a strategy to modify the interface between the hole transport layer and the perovskite emissive layer with an amphiphilic conjugated polymer of poly[(9,9-bis(3-(N,N-dimethylamino)propy1)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN). We show evidences that PFN improves the quality of the perovskite film, which effectively suppresses nonradiative recombination. By further improving the charge injection balance rate, a green perovskite LED with a champion current efficiency of 45.2 cd/A, corresponding to an external quantum efficiency of 14.4%, is achieved. In addition, the device based on the PFN layer exhibits improved operational lifetime. Our work paves a facile way for the development of efficient and stable perovskite LEDs.

  • 707.
    Zou, Yatao
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. Soochow Univ, Peoples R China.
    Xu, Hao
    Soochow Univ, Peoples R China.
    Li, Siying
    Soochow Univ, Peoples R China.
    Song, Tao
    Soochow Univ, Peoples R China.
    Kuai, Liang
    Soochow Univ, Peoples R China.
    Bai, Sai
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Sun, Baoquan
    Soochow Univ, Peoples R China.
    Spectral-Stable Blue Emission from Moisture-Treated Low-Dimensional Lead Bromide-Based Perovskite Films2019Ingår i: ACS Photonics, E-ISSN 2330-4022, Vol. 6, nr 7, s. 1728-1735Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Highly efficient light-emitting diodes (LEDs) based on metal halide perovskites with green, red, and near-infrared electro-luminescence have been widely demonstrated. However, the development of their blue counterparts is still hampered due to the difficult deposition of efficient and spectral-stable blue-emitting active layers. Here, we report a facile and general approach that uses a moisture treatment in combination with the precursor stoichiometry engineering for the fabrication of efficient and color stable blue-emitting perovskite films. We find that, with a short-term moisture exposure, light emission from Ruddlesden Popper lead bromide-based perovskite films exhibit a continuous blue-shift from 512 to 475 nm through incorporating excess CsBr in the precursors. In addition, we observe that the formed Cs4PbBr6 phase under CsBr-rich condition is favorable to stabilize the blue emission of the resulting films. The corresponding blue-emitting perovskite films exhibit a photoluminescence quantum efficiency of over 20%, delivering sky-blue perovskite LEDs with no change in the light emission even under high voltage. Our strategy provides an alternative way for realizing efficient and spectrally stable active layers for the further development of blue-emitting perovskite LEDs.

  • 708.
    Åsberg, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hydrogels of conjugated polyelectrolytes for biosensor and biochip applications2005Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis describes the use of conjugated polyelectrolytes (CPEs) in biosensor devices. The method is based on non-covalent assembly of the biomolecule of interest and the CPE functioning as the reporter, in one case as a transducer, of biomolecular events. Devices of these assemblies on solid supports that can operate in liquid solutions have been the focus. Polythiophenes, both semiconducting and conducting, is the class of materials that has been used in this work. The semiconducting polythiophenes have ionic side chains which makes them water soluble. This ionic side chain is capable of both forming electrostatic and hydrogen bonds, and when paired with the hydrophobic backbone of the polymer a great number of interactions with biomolecules are possible. The highly conducting polythiophene derivative PEDOT -PSS, (PEDOT) doped with ionic and water soluble PSS polyelectrolyte, was used as the conducting material in 3D-electrode. Both the semiconducting and conducting polymers described above forms hydrogels on solid supports if crosslinked with the appropriate ion, biomolecule or polymer. Evaluation of the CPEs, both with and without biomolecules, was performed in liquid, solid and hydrogel state using a number of techniques. This was done to understand how the CPEs behave when exposed to different buffer systems and various biomolecules.

    Hydrogels of conjugated polyelectrolytes combined with biomolecules are attractive as biosensors. The advantage with the hydrogel format is the high water content, the porous structure and the large capacity of binding molecules. High water content is important to preserve the biomolecules by providing the correct buffered environment. In this thesis we demonstrated a hydrogel of the highly conducting PEDOT -PSS polymer that was crosslinked on a solid support together with horseradish peroxidase (HRP) enzyme, forming an enzyme-enhanced electrode. Further studies of hydrogels were done using in situ quartz crystal microbalance with dissipation (QCM-D). POWT is a CPE withproperties well suited for biochip applications and readily forms hydrogels when exposed to water-based buffer solutions or biomolecule solutions. Detection ofcomplementary DNA and rejection of non-complementary DNA in a POWT hydrogel was demonstrated. The interaction between POWT and DNAoligonucleotides was also evaluated using fluorescence resonance energy transfer (FRET) in solution. Labeled DNA oligonucleotides with energy accepting or donating fluorophores allowed us to determine distance and binding stoichiometry in the non-covalent POWT-DNA complex.

    Patterning and anchoring of biomolecules and non-covalent assembled CPE-biomolecule complexes to a chip surface was studied; in the adsorbed state these complexes are hydrogels. Our novel method is based on the modification of the surface energy of a hydrophilic substrate surface using hydrophobic poly(dimethylsiloxane) (PDMS) elastomer stamp containing a relief pattern. Different conformations in biomolecules could be detected using fluorescence microscopy, where the CPEs acts as reporters and the PDMS modified substrates as discriminator. Also, excellent enzyme activity in patterned CPE/Horseradish peroxidase (HRP) enzyme was shown.

    Distances between the individual molecules in solid state devices of conjugated polymers can be small. In luminescence devices, such as light emitting diodes or fluorescence biosensors, there is a chance of interaction between conjugated molecules especially if more than one type of molecule is present. Quenching of the light and fluorescence energy transfer can occur and a simple approach to study this was developed.

    Delarbeten
    1. Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode
    Öppna denna publikation i ny flik eller fönster >>Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode
    2003 (Engelska)Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 19, nr 3, s. 199-207Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    We have utilized the highly conducting poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) aqueous dispersion (PEDOT/PSS) to build a conducting hydrogel matrix. Together with appropriate biomolecules this constitutes a hydrogel bio-electrode. The open hydrogel structure makes diffusion of analytes surrounding the cells into the matrix electrode easier. If enzymes are utilized, osmium is used as mediator between the prosthetic group of the enzyme and the conducting polymer matrix. Osmium also functions as a crosslink point to poly-4-vinylpyridine, which together with the magnesium crosslinked PEDOT/PSS gives a rigid hydrogel. The enzyme Horseradish peroxidase (HRP) was used as a model enzyme to evaluate the enzyme-enhanced electrode. We evaluated the electrode at pH 7, which is the pH choice for many biological systems. From cyclic voltammetry (CV) measurements we deduced that a very low reduction potential was needed to reduce the prosthetic group. Constant potential amperometry were performed to demonstrate the biosensor capabilities. A differential sensitivity of 0.13 A M−1 cm−2 through the 0–30 μM concentration range was achieved. Both the biostability and the influence on conductivity, important aspects when for example making nerve- or cell-electrodes, were investigated.

    Nyckelord
    Biomolecule electrode, Conjugated polymer, Horseradish peroxidase, Hydrogel, Osmium, PEDOT/PSS
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-46422 (URN)10.1016/S0956-5663(03)00220-3 (DOI)
    Tillgänglig från: 2009-10-11 Skapad: 2009-10-11 Senast uppdaterad: 2017-12-13
    2. Hydrogels from a water-soluble Zwitterionic polythiophene: dynamics under pH change and biomolecular interactions observed using quartz crystal microbalance with dissipation monitoring
    Öppna denna publikation i ny flik eller fönster >>Hydrogels from a water-soluble Zwitterionic polythiophene: dynamics under pH change and biomolecular interactions observed using quartz crystal microbalance with dissipation monitoring
    2005 (Engelska)Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, nr 16, s. 7292-7298Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The water-soluble zwitterionic polythiophene, poly(3-((S)-5-amino-5- carboxyl-3-oxapentyl)-2,5-thiophene) hydrochloride (POWT), is a conjugated polyelectrolyte (CPE) with properties well suited for biochip applications. CPEs readily form hydrogels when exposed to water-based buffer solutions or biomolecule solutions. In this work, we used in situ quartz crystal microbalance with dissipation (QCM-D) monitoring to collect information on the interaction between POWT films exposed to buffers with different pH and POWT/DNA chains. Our data show that POWT swells significantly when exposed to low-pH buffers, such as pH 4 acetate, this is seen as an increase in thickness and decrease in viscosity obtained via a Voight-based modeling of combined f and D QCM-D measurements. The magnitude of thickness and viscosity change upon changing from a pH 10 carbonate buffer to pH 4 acetate is 100% increase in thickness and 50% decrease in viscosity. The response of the hydrogel under pH change is well correlated with fluorescence data from POWT films on glass. The state of the hydrogel is important during interaction with biomolecules; illustrated by the observation that a swollen CPE hydrogel adsorbs a higher amount of DNA than a compacted one. In agreement with previous results, the QCM-D data confirmed that the POWT/DNA hydrogel sense complementary DNA specifically and with negligible binding of noncomplementary DNA. These results are important for efficient constructions of biochips in water environments using this class of materials.

    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-12726 (URN)10.1021/la050479e (DOI)
    Tillgänglig från: 2007-12-07 Skapad: 2007-12-07 Senast uppdaterad: 2017-12-14
    3. Interactions between a zwitterionic polythiophene derivative and oligonucleotides as resolved by fluorescence resonance energy transfer
    Öppna denna publikation i ny flik eller fönster >>Interactions between a zwitterionic polythiophene derivative and oligonucleotides as resolved by fluorescence resonance energy transfer
    2005 (Engelska)Ingår i: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 17, nr 16, s. 4204-4211Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The interactions between a zwitterionic polythiophene derivative, POWT, and DNA oligonucleotides in solution have been studied by FRET (fluorescence resonance energy transfer). When POWT and ssDNA are bound alone in a complex, the distance between them is at its smallest. The distance increases when adding complementary DNA, but POWT is still mainly bound to the first DNA strand. We find that two POWT chains bind to one DNA strand, and the two POWT chains seem held together in pairs, unable to separate, as they can only bind to and quench half their own amount of labeled DNA. This POWT−POWT complex appears to dissociate at lower concentrations. ssDNA attached to POWT in a complex can also be substituted by other ssDNA in solution; this occurs to 50% when the free DNA is present in 10-fold concentration compared to the ssDNA bound to POWT. Titration studies at different concentrations show positive cooperativity in the binding of POWT and ssDNA into a complex. The hybridization of complementary DNA to the same complex involves no cooperativity. These observations indicate interesting possibilities for the use of POWT as a DNA sensor.

    Nationell ämneskategori
    Naturvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-30356 (URN)10.1021/cm050328x (DOI)15901 (Lokalt ID)15901 (Arkivnummer)15901 (OAI)
    Tillgänglig från: 2009-10-09 Skapad: 2009-10-09 Senast uppdaterad: 2017-12-13
    4. Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers
    Öppna denna publikation i ny flik eller fönster >>Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers
    2004 (Engelska)Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 96, nr 6, s. 3140-3147Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Here we present a simple approach to study the interaction of singlet excitons with polarons in conjugated polymers in organic electronic devices. Interlayer quenching constants KIL of 1.5 M−1 between a fluorescent molecule and a doped polymer in a layered sample demonstrates the importance of understanding the quenching of excited states in polymeric devices. A combination of Förster resonance energy transfer and quenching of photoluminescence between a fluorescent molecule and a conjugated polymer in its semiconducting and metallic states were studied. The polymer is a chiral 3-substituted polythiophene (POWT) and the fluorescent molecule is fluorescein bound to dextran (D-FITC). Bilayer samples with fluorescein on top of the POWT were fabricated and studied with absorption spectroscopy, fluorescence microscopy, and electrochemical doping methods. When POWT is electrochemically dedoped it is possible to enhance the photoluminescence in the polymer layer by excitation transfer from the fluorescein layer. Our results demonstrate that PL from the polythiophene disappears rapidly as soon as the layer is doped. As the doping of polymer layer increases the fluorescence from the fluorescein on top of the polymer decreases, due to excitation quenching. Models for excitation transfer and excitation quenching in POWT/FITC bilayer devices have been developed. This model predicts a linear relationship between the PL from the two molecules, in agreement with our experimental findings. These results are relevant for the development of electroluminescent devices or solar cells based on conjugated polymers.

    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-45631 (URN)10.1063/1.1774247 (DOI)
    Tillgänglig från: 2009-10-11 Skapad: 2009-10-11 Senast uppdaterad: 2017-12-13
    5. Surface energy modified chips for detection of conformational states and enzymatic activity in biomolecules
    Öppna denna publikation i ny flik eller fönster >>Surface energy modified chips for detection of conformational states and enzymatic activity in biomolecules
    2006 (Engelska)Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 22, nr 5, s. 2205-2211Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    A novel patterning method for anchoring biomolecules and noncovalent assembled conjugated polyelectrolyte (CPE)/biomolecule complexes to a chip surface is presented. The surface energy of a hydrophilic substrate is modified using an elastomeric poly(dimethylsiloxane) (PDMS) stamp, containing a relief pattern. Modification takes place on the parts where the PDMS stamp is in conformal contact with the substrate and leaves low molecular weight PDMS residues on the surface resulting in a hydrophobic modification, and then biomolecules and CPE/biomolecule complexes are then adsorbed in a specific pattern. The method constitutes a discrimination system for different conformations in biomolecules using CPEs as reporters and the PDMS modified substrates as the discriminator. Detection of different conformations in two biomacromolecules, a synthetic peptide (JR2E) and a protein (calmodulin), reported by the CPE and resolved by fluorescence was demonstrated. Also, excellent enzyme activity in patterned CPE/horseradish peroxidase (HRP) enzyme was shown, demonstrating that this method can be used to pattern biomolecules with their activity retained. The method presented could be useful in various biochip applications, such as analyzing proteins and peptides in large-scale production, in making metabolic chips, and for making multi-microarrays.

    Nationell ämneskategori
    Naturvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-34580 (URN)10.1021/la0527902 (DOI)22009 (Lokalt ID)22009 (Arkivnummer)22009 (OAI)
    Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2017-12-13
  • 709.
    Åsberg, Peter
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Björk, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Höök, Fredrik
    Solid State Physics, Lund University, Lund, Sweden .
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hydrogels from a water-soluble Zwitterionic polythiophene: dynamics under pH change and biomolecular interactions observed using quartz crystal microbalance with dissipation monitoring2005Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, nr 16, s. 7292-7298Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The water-soluble zwitterionic polythiophene, poly(3-((S)-5-amino-5- carboxyl-3-oxapentyl)-2,5-thiophene) hydrochloride (POWT), is a conjugated polyelectrolyte (CPE) with properties well suited for biochip applications. CPEs readily form hydrogels when exposed to water-based buffer solutions or biomolecule solutions. In this work, we used in situ quartz crystal microbalance with dissipation (QCM-D) monitoring to collect information on the interaction between POWT films exposed to buffers with different pH and POWT/DNA chains. Our data show that POWT swells significantly when exposed to low-pH buffers, such as pH 4 acetate, this is seen as an increase in thickness and decrease in viscosity obtained via a Voight-based modeling of combined f and D QCM-D measurements. The magnitude of thickness and viscosity change upon changing from a pH 10 carbonate buffer to pH 4 acetate is 100% increase in thickness and 50% decrease in viscosity. The response of the hydrogel under pH change is well correlated with fluorescence data from POWT films on glass. The state of the hydrogel is important during interaction with biomolecules; illustrated by the observation that a swollen CPE hydrogel adsorbs a higher amount of DNA than a compacted one. In agreement with previous results, the QCM-D data confirmed that the POWT/DNA hydrogel sense complementary DNA specifically and with negligible binding of noncomplementary DNA. These results are important for efficient constructions of biochips in water environments using this class of materials.

  • 710.
    Åsberg, Peter
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode2003Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 19, nr 3, s. 199-207Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have utilized the highly conducting poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) aqueous dispersion (PEDOT/PSS) to build a conducting hydrogel matrix. Together with appropriate biomolecules this constitutes a hydrogel bio-electrode. The open hydrogel structure makes diffusion of analytes surrounding the cells into the matrix electrode easier. If enzymes are utilized, osmium is used as mediator between the prosthetic group of the enzyme and the conducting polymer matrix. Osmium also functions as a crosslink point to poly-4-vinylpyridine, which together with the magnesium crosslinked PEDOT/PSS gives a rigid hydrogel. The enzyme Horseradish peroxidase (HRP) was used as a model enzyme to evaluate the enzyme-enhanced electrode. We evaluated the electrode at pH 7, which is the pH choice for many biological systems. From cyclic voltammetry (CV) measurements we deduced that a very low reduction potential was needed to reduce the prosthetic group. Constant potential amperometry were performed to demonstrate the biosensor capabilities. A differential sensitivity of 0.13 A M−1 cm−2 through the 0–30 μM concentration range was achieved. Both the biostability and the influence on conductivity, important aspects when for example making nerve- or cell-electrodes, were investigated.

  • 711.
    Åsberg, Peter
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers2004Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 96, nr 6, s. 3140-3147Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Here we present a simple approach to study the interaction of singlet excitons with polarons in conjugated polymers in organic electronic devices. Interlayer quenching constants KIL of 1.5 M−1 between a fluorescent molecule and a doped polymer in a layered sample demonstrates the importance of understanding the quenching of excited states in polymeric devices. A combination of Förster resonance energy transfer and quenching of photoluminescence between a fluorescent molecule and a conjugated polymer in its semiconducting and metallic states were studied. The polymer is a chiral 3-substituted polythiophene (POWT) and the fluorescent molecule is fluorescein bound to dextran (D-FITC). Bilayer samples with fluorescein on top of the POWT were fabricated and studied with absorption spectroscopy, fluorescence microscopy, and electrochemical doping methods. When POWT is electrochemically dedoped it is possible to enhance the photoluminescence in the polymer layer by excitation transfer from the fluorescein layer. Our results demonstrate that PL from the polythiophene disappears rapidly as soon as the layer is doped. As the doping of polymer layer increases the fluorescence from the fluorescein on top of the polymer decreases, due to excitation quenching. Models for excitation transfer and excitation quenching in POWT/FITC bilayer devices have been developed. This model predicts a linear relationship between the PL from the two molecules, in agreement with our experimental findings. These results are relevant for the development of electroluminescent devices or solar cells based on conjugated polymers.

  • 712.
    Åsberg, Peter
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Surface energy modified chips for detection of conformational states and enzymatic activity in biomolecules2006Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 22, nr 5, s. 2205-2211Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel patterning method for anchoring biomolecules and noncovalent assembled conjugated polyelectrolyte (CPE)/biomolecule complexes to a chip surface is presented. The surface energy of a hydrophilic substrate is modified using an elastomeric poly(dimethylsiloxane) (PDMS) stamp, containing a relief pattern. Modification takes place on the parts where the PDMS stamp is in conformal contact with the substrate and leaves low molecular weight PDMS residues on the surface resulting in a hydrophobic modification, and then biomolecules and CPE/biomolecule complexes are then adsorbed in a specific pattern. The method constitutes a discrimination system for different conformations in biomolecules using CPEs as reporters and the PDMS modified substrates as the discriminator. Detection of different conformations in two biomacromolecules, a synthetic peptide (JR2E) and a protein (calmodulin), reported by the CPE and resolved by fluorescence was demonstrated. Also, excellent enzyme activity in patterned CPE/horseradish peroxidase (HRP) enzyme was shown, demonstrating that this method can be used to pattern biomolecules with their activity retained. The method presented could be useful in various biochip applications, such as analyzing proteins and peptides in large-scale production, in making metabolic chips, and for making multi-microarrays.

  • 713.
    Åslund, Andreas
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Organisk Kemi. Linköpings universitet, Tekniska högskolan.
    Herland, Anna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hammarström, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biokemi. Linköpings universitet, Tekniska högskolan.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Organisk Kemi. Linköpings universitet, Tekniska högskolan.
    Jonsson, Bengt-Harald
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär Bioteknik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Konradsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Organisk Kemi. Linköpings universitet, Tekniska högskolan.
    Studies of luminescent conjugated polythiophene derivatives-Enhanced spectral discrimination of protein conformational states2007Ingår i: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 18, nr 6, s. 1860-1868Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Improved probes for amyloid fibril formation are advantageous for the early detection and better understanding of this disease-associated process. Here, we report a comparative study of eight luminescent conjugated polythiophene derivates (LCPs) and their discrimination of a protein (insulin) in the native or amyloid-like fibrillar state. For two of the LCPs, the synthesis is reported. Compared to their monomer-based analogues, trimer-based LCPs showed significantly better optical signal specificity for amyloid-like fibrils, seen from increased quantum yield and spectral shift. The trimer-based LCPs alone were highly quenched and showed little interaction with native insulin, as seen from analytical ultracentrifugation and insignificant spectral differences from the trimer-based LCP in buffered and native protein solution. Hence, the trimer-based LCPs showed enhanced discrimination between the amyloid-like fibrillar state and the corresponding native protein.

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