Serge Cosnier - Academia.edu (original) (raw)

Papers by Serge Cosnier

Research paper thumbnail of Flotation Assembly of Large-Area Ultrathin MWCNT Nanofilms for Construction of Bioelectrodes

Nanomaterials (Basel, Switzerland), Jan 21, 2017

We report a simple, versatile, and rapid method for the fabrication of optically-transparent larg... more We report a simple, versatile, and rapid method for the fabrication of optically-transparent large-area carbon nanotube (CNT) films via flotation assembly. After solvent-induced assembly, floating films were transferred to a flat supporting substrate to form conductive and transparent CNT film electrodes. The resulting electrodes, with uniform 40 ± 20 nm multi-walled CNT (MWCNT) layers, were characterized by electrochemical and microscopy methods. The flotation method does not require specialized thin-film instrumentation and avoids the need for surfactants and pre-oxidized CNTs which can hamper electrochemical performance. A proof-of-concept nanostructured bioelectrode demonstrating high sensitivity for glucose was developed with an electropolymerized poly(pyrene-adamantane) layer for host-guest immobilization of active β-cyclodextrin tagged GOx enzymes. The polymer provides pyrene groups for cross-linking to CNTs and pendant adamantane groups for binding the β-cyclodextrin groups ...

Research paper thumbnail of Direct electrochemistry and electrocatalysis of glucose oxidase immobilized on reduced graphene oxide and silver nanoparticles nanocomposite modified electrode

Research paper thumbnail of Functionalizable Glyconanoparticles for a Versatile Redox Platform

Nanomaterials

A series of new glyconanoparticles (GNPs) was obtained by self-assembly by direct nanoprecipitati... more A series of new glyconanoparticles (GNPs) was obtained by self-assembly by direct nanoprecipitation of a mixture of two carbohydrate amphiphilic copolymers consisting of polystyrene-block-β-cyclodextrin and polystyrene-block-maltoheptaose with different mass ratios, respectively 0–100, 10–90, 50–50 and 0–100%. Characterizations for all these GNPs were achieved using dynamic light scattering, scanning and transmission electron microscopy techniques, highlighting their spherical morphology and their nanometric size (diameter range 20–40 nm). In addition, by using the inclusion properties of cyclodextrin, these glyconanoparticles were successfully post-functionalized using a water-soluble redox compound, such as anthraquinone sulfonate (AQS) and characterized by cyclic voltammetry. The resulting glyconanoparticles exhibit the classical electroactivity of free AQS in solution. The amount of AQS immobilized by host–guest interactions is proportional to the percentage of polystyrene-block...

Research paper thumbnail of Wearable Biosupercapacitor: Harvesting and Storing Energy from Sweat

Advanced Functional Materials

Research paper thumbnail of Stretchable and Flexible Buckypaper‐Based Lactate Biofuel Cell for Wearable Electronics

Advanced Functional Materials

Research paper thumbnail of Comparison of Commercial and Lab-made MWCNT Buckypaper: Physicochemical Properties and Bioelectrocatalytic O2 Reduction

Research paper thumbnail of Buckypaper bioelectrodes: emerging materials for implantable and wearable biofuel cells

Energy & Environmental Science

Carbon nanotubes (CNTs) have been widely exploited for the development of enzymatic biofuel cells... more Carbon nanotubes (CNTs) have been widely exploited for the development of enzymatic biofuel cells with sufficient power densities in the μW to mW range for operating low-power bioelectronic devices from renewable substrates.

Research paper thumbnail of DNA-Mediated Nanoscale Metal-Organic Frameworks for Ultrasensitive Photoelectrochemical Enzyme-Free Immunoassay

Analytical chemistry, Jan 20, 2018

A novel enzyme-free photoelectrochemical (PEC) immunoassay was developed for the ultrasensitive d... more A novel enzyme-free photoelectrochemical (PEC) immunoassay was developed for the ultrasensitive detection of prostate specific antigen (PSA) based on the DNA-mediated nanoscale zirconium-porphyrin MOFs (NMOFs). By virtue of the intrinsic coordination between unsaturated zirconium sites of the NMOFs frameworks and phosphonate groups, the 5'-phosphorylared ss-DNA-tagged antibody (Ab-DNA) conjugate with a consecutive stretch of guanines as a spacer could be loaded on the NMOFs easily, obtaining a novel type of Ab-DNA-functionalized NMOFs complex. Additionally, as a photocathode PEC active nanomaterial, NMOFs exhibited a significant enhanced photocurrent response with the presence of dopamine under oxygen-containing aqueous media at -0.3 V (vs Ag/AgCl). Furthermore, with the aid of the electrochemical grafting of polyamidoamine (PAMAM) dendrimers functionalized interface, the novel type of Ab-DNA-NMOFs further served as PEC signal nanoprobe for the ultrasensitive PSA immunoassay. Un...

Research paper thumbnail of Dawson-type polyoxometalate nanoclusters confined in a carbon nanotube matrix as efficient redox mediators for enzymatic glucose biofuel cell anodes and glucose biosensors

Biosensors & bioelectronics, Jan 30, 2018

Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (CHN)[PMoO]·4H... more Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (CHN)[PMoO]·4HO (PMo) and (CHNO)[HPWO]·6HO (PW) are reported as mediators for electron transfer between FAD-dependent glucose dehydrogenase (FAD-GDH) and a multiwalled carbon nanotube (MWCNT) matrix for glucose biofuel cell and biosensor applications. These polyoxometalates were chosen due to their promising redox behavior in a potential range for mediated electron transfer with the glucose oxidizing enzyme, FAD-GDH. PMo and PW were immobilized on 1-pyrenemethylamine (PMA) functionalized MWCNT deposits. After immobilization of FAD-GDH, the PW-modified MWCNT electrode demonstrated mediated electron transfer and provided a catalytic current density of 0.34 mA cm at 0.2 V vs SCE with an open circuit potential (OCP) of -0.08 V vs SCE. A 10-fold increase in catalytic current to 4.7 mA cm at 0.2 V vs SCE and a slightly lower OCP of -0.10 V vs SCE was observed for an equivalent electrode modified with PMo.Th...

Research paper thumbnail of Redox-Active Glyconanoparticles as Electron Shuttles for Mediated Electron Transfer with Bilirubin Oxidase in Solution

Journal of the American Chemical Society, Nov 15, 2017

We demonstrate self-assembly, characterization and bioelectrocatalysis of redox-active cyclodextr... more We demonstrate self-assembly, characterization and bioelectrocatalysis of redox-active cyclodextrin-coated nanoparticles. The nanoparticles with host-guest functionality are easy to assemble and permit entrapment of hydrophobic redox molecules in aqueous solution. Bis-pyrene-ABTS encapsulated nanoparticles were investigated electrochemically and spectroscopically. Their use as electron shuttles is demonstrated via an intraelectron transfer chain between neighboring redox units of clustered particles (Dh,DLS = 195 nm) and the mono- and trinuclear Cu sites of bilirubin oxidases. Enhanced current densities for mediated O2 reduction are observed with the redox nanoparticle system compared to equivalent bioelectrode cells with dissolved mediator. Improved catalytic stability over 2 days was also observed with the redox nanoparticles, highlighting a stabilizing effect of the polymeric architecture. Bioinspired nanoparticles as mediators for bioelectrocatalysis promises to be valuable for ...

Research paper thumbnail of Electrocatalytic oxidation of alcohols on carbon electrodes modified by functionalized polypyrrole–RuO2 films

Journal of Molecular Catalysis

The electrocatalytic activity of several types of polypyrrole films bearing cationic pendant grou... more The electrocatalytic activity of several types of polypyrrole films bearing cationic pendant group [tris@ipyridyl)ruthenium(II) complexes, viologen, ammonium] and containing dispersed microparticles of RuOe towards the oxidation of alcohols to aldehydes or ketones has been investigated. Best results are obtained with polypyrrole films substituted by a tris(bipyridyl)ruthenium(II) complex, the latter acting as an electron relay for the electrogeneration of the strong oxidizing species RuOz-. The influence of several parameters such as base, supporting electrolyte, electrolysis potential and catalyst amount on the efficiency of the electrocatalysis has been examined. Under optimum conditions a maximum turnover of 10 900 was reached. In all cases the lifetime of these electrode materials was limited by the slow release of the RuO:-species.

Research paper thumbnail of A High Power Buckypaper Biofuel Cell: Exploiting 1,10-Phenanthroline-5,6-dione with FAD-Dependent Dehydrogenase for Catalytically-Powerful Glucose Oxidation

Research paper thumbnail of Graphene/clay composite electrode formed by exfoliating graphite with Laponite for simultaneous determination of ascorbic acid, dopamine, and uric acid

Monatshefte für Chemie - Chemical Monthly

ABSTRACT Laponite/graphene composite (Lap/G) was prepared by directly exfoliating graphite with L... more ABSTRACT Laponite/graphene composite (Lap/G) was prepared by directly exfoliating graphite with Laponite under mechanical grinding. The morphologies and intrinsic physical properties of Lap/G were characterized by transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy. Electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry were used to investigate the electrochemical behavior of Lap/G-modified electrodes. The resulting Lap/G composite exhibited good electroconductivity combined with electrocatalytic activity towards oxidation of small biomolecules such as dopamine. Furthermore, the resulting Lap/G-modified glassy carbon electrodes were applied for simultaneous determination of ascorbic acid, dopamine, and uric acid.

Research paper thumbnail of Towards a Versatile Photoreactive Platform for Biosensing Applications

Journal of Analysis and Testing

An original interfacial hybrid cross-linker molecule combined electrochemical and photochemical p... more An original interfacial hybrid cross-linker molecule combined electrochemical and photochemical properties by substitution of two functional groups, pyrene, and diazirine. The first group enables anchoring by strong p-stacking interaction or by electropolymerization onto multi-walled carbon nanotubes (MWCNT). The other photoreactive group allows the covalent link with biomolecules under long-wavelength UV illumination. Diazirine was chosen due to its ability to photogenerate high reactive radicals under UV irradiation. The photoreactivity of these immobilized nanostructured conductive surfaces was tested towards the covalent attachment of tyrosinase which is well known to oxidize a large range of phenolic compounds and its yield and availability was evaluated by amperometric measurements of catechol by using molecular dioxygen. The architecture exhibiting the best analytical characteristics obtained for catechol was then chosen to detect dopamine.

Research paper thumbnail of Zirconium-Based Porphyrinic Metal-Organic Framework (PCN-222): Enhanced Photoelectrochemical Response and Its Application for Label-Free Phosphoprotein Detection

Analytical chemistry, Jan 15, 2016

A simple and rapid photoelectrochemical (PEC) sensor was developed for the label-free detection o... more A simple and rapid photoelectrochemical (PEC) sensor was developed for the label-free detection of a phosphoprotein (α-casein) based on a zirconium based porphyrinic metal-organic framework (MOF), PCN-222, which exhibited an enhanced photocurrent response toward dopamine under the O2-saturated aqueous media. In this work, in terms of PEC measurements and cyclic voltammetry, the PEC behaviors of PCN-222 in aqueous media were thoroughly investigated for the first time. Additionally, in the virtue of the steric hindrance effect from the coordination of the phosphate groups and inorganic Zr-O clusters as binding sites in PCN-222, this biosensor showed high sensitivity for detecting α-casein and the limit of detection (LOD) was estimated to be 0.13 μg mL(-1). Moreover, the proposed method provides a promising platform for clinic diagnostic and therapeutics.

Research paper thumbnail of Synergetic Effects of Combined Nanomaterials for Biosensing Applications

Sensors (Basel, Switzerland), Jan 3, 2017

Nanomaterials have become essential components for the development of biosensors since such nanos... more Nanomaterials have become essential components for the development of biosensors since such nanosized compounds were shown to clearly increase the analytical performance. The improvements are mainly related to an increased surface area, thus providing an enhanced accessibility for the analyte, the compound to be detected, to the receptor unit, the sensing element. Nanomaterials can also add value to biosensor devices due to their intrinsic physical or chemical properties and can even act as transducers for the signal capture. Among the vast amount of examples where nanomaterials demonstrate their superiority to bulk materials, the combination of different nano-objects with different characteristics can create phenomena which contribute to new or improved signal capture setups. These phenomena and their utility in biosensor devices are summarized in a non-exhaustive way where the principles behind these synergetic effects are emphasized.

Research paper thumbnail of In situ formed copper nanoparticles templated by TdT-mediated DNA for enhanced SPR sensor-based DNA assay

Biosensors & bioelectronics, Jan 15, 2017

For the efficient surface plasmon resonance (SPR)-based DNA assay researching, signal amplificati... more For the efficient surface plasmon resonance (SPR)-based DNA assay researching, signal amplification tactics were absolutely necessary. In this work, a sensitive SPR-DNA sensor was developed by employing in situ synthesis of copper nanoparticles (CuNPs) templated by poly-T sequences DNA from terminal deoxynucleotidyl transferase (TdT)-mediated extension, and synergistically with nano-effect deposition as the mass relay. The objective of this strategy was manifold: firstly, tDNA hybridized with the optimal designed probes to active the TdT-mediated DNA extension onto the surface of SPR chip, resulted a long poly-T sequences ssDNA chain in dsDNA terminal onto surface of gold chip and characterized by SPR signal amplitudes. Secondly, copper ion (Cu(2+)) adsorbed into the skeleton of poly-T sequences DNA, with the aid of ascorbic acid (VC) to achieve the Cu(2+) reduction, copper nanostructures (CuNPs) was synchronously generated onto the single nucleotide chain anchoring in dsDNA derivat...

Research paper thumbnail of Enhanced Electrochemiluminescence of One-Dimensional Self-Assembled Porphyrin Hexagonal Nanoprisms

ACS applied materials & interfaces, Jan 21, 2017

In this work, we synthesized the one-dimensional nanostructure of zinc 5,10,15,20-tetra(4-pyridyl... more In this work, we synthesized the one-dimensional nanostructure of zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP) via a self-assembly technique. Using sodium dodecyl sulfate (SDS) as "soft template", the self-assembled ZnTPyP (SA-ZnTPyP) had the morphology of hexagonal nanoprisms with a uniform size (diameter of 100 nm). The SA-ZnTPyP exhibited remarkably different spectral properties compared to those of the original ZnTPyP. The as-prepared SA-ZnTPyP was used to modify glassy carbon electrodes (GCE), and the electrochemiluminescence (ECL) behaviors of the SA-ZnTPyP/GCE were investigated. The hydrophilic carbon dots (C-dots) could efficiently prevent the dissolution of SA-ZnTPyP in DMF containing 0.1 mol L(-1) TBAP and, simultaneously, could accelerate electron transfer. Therefore, the enhanced ECL was realized by C-dots/SA-ZnTPyP/GCE by using H2O2 as co-reactant. This amplification of ECL was further studied by ECL spectroscopies and cyclic voltammetry, and the...

Research paper thumbnail of Controlled carbon nanotube layers for impedimetric immunosensors: High performance label free detection and quantification of anti-cholera toxin antibody

Biosensors & bioelectronics, Jan 15, 2017

An original impedimetric immunosensor was developed based on carbon nanotube (CNT) deposits with ... more An original impedimetric immunosensor was developed based on carbon nanotube (CNT) deposits with controlled thicknesses for enhanced electroactive surface areas leading to improved sensor performances. Cholera monitoring was chosen as the model immune system for this setup. These CNT deposits were characterized using confocal laser microscopy and electrochemical methods. To form the sensor device, the CNT deposits were functionalized via electrocoating of polypyrrole-nitrilotriacetic acid (poly(pyrrole-NTA)) followed by the formation of a Cu (II) complex with the NTA functions. The bioreceptor unit, cholera toxin B Subunit, modified with biotin, was then immobilized via coordination of the biotin groups with the NTA-Cu(II) complex. Each step of the formation of the immunosensor and the subsequent binding of the analyte antibody anti-cholera toxin were investigated with cyclic voltammetry and Electrochemical Impedance Spectroscopy. After optimization, the resulting impedimetric chole...

Research paper thumbnail of Assembly and Stacking of Flow-through Enzymatic Bioelectrodes for High Power Glucose Fuel Cells

ACS applied materials & interfaces, Jan 19, 2017

Bioelectrocatalytic carbon nanotube based pellets comprising redox enzymes were directly integrat... more Bioelectrocatalytic carbon nanotube based pellets comprising redox enzymes were directly integrated in a newly conceived flow-through fuel cell. Porous electrodes and a separating cellulose membrane were housed in a glucose/oxygen biofuel cell design with inlets and outlets allowing the flow of electrolyte through the entire fuel cell. Different flow setups were tested and the optimized single cell setup, exploiting only 5 mmol L(-1) glucose, showed an open circuit voltage (OCV) of 0.663 V and provided 1.03 ± 0.05 mW at 0.34 V. Furthermore, different charge/discharge cycles at 500 Ω and 3 kΩ were applied to optimize long-term stability leading to 3.6 J (1 mW h) of produced electrical energy after 48 h. Under continuous discharge at 6 kΩ, about 0.7 mW h could be produced after a 24 h period. The biofuel cell design further allows a convenient assembly of several glucose biofuel cells in reduced volumes and their connection in parallel or in series. The configuration of two biofuel ce...

Research paper thumbnail of Flotation Assembly of Large-Area Ultrathin MWCNT Nanofilms for Construction of Bioelectrodes

Nanomaterials (Basel, Switzerland), Jan 21, 2017

We report a simple, versatile, and rapid method for the fabrication of optically-transparent larg... more We report a simple, versatile, and rapid method for the fabrication of optically-transparent large-area carbon nanotube (CNT) films via flotation assembly. After solvent-induced assembly, floating films were transferred to a flat supporting substrate to form conductive and transparent CNT film electrodes. The resulting electrodes, with uniform 40 ± 20 nm multi-walled CNT (MWCNT) layers, were characterized by electrochemical and microscopy methods. The flotation method does not require specialized thin-film instrumentation and avoids the need for surfactants and pre-oxidized CNTs which can hamper electrochemical performance. A proof-of-concept nanostructured bioelectrode demonstrating high sensitivity for glucose was developed with an electropolymerized poly(pyrene-adamantane) layer for host-guest immobilization of active β-cyclodextrin tagged GOx enzymes. The polymer provides pyrene groups for cross-linking to CNTs and pendant adamantane groups for binding the β-cyclodextrin groups ...

Research paper thumbnail of Direct electrochemistry and electrocatalysis of glucose oxidase immobilized on reduced graphene oxide and silver nanoparticles nanocomposite modified electrode

Research paper thumbnail of Functionalizable Glyconanoparticles for a Versatile Redox Platform

Nanomaterials

A series of new glyconanoparticles (GNPs) was obtained by self-assembly by direct nanoprecipitati... more A series of new glyconanoparticles (GNPs) was obtained by self-assembly by direct nanoprecipitation of a mixture of two carbohydrate amphiphilic copolymers consisting of polystyrene-block-β-cyclodextrin and polystyrene-block-maltoheptaose with different mass ratios, respectively 0–100, 10–90, 50–50 and 0–100%. Characterizations for all these GNPs were achieved using dynamic light scattering, scanning and transmission electron microscopy techniques, highlighting their spherical morphology and their nanometric size (diameter range 20–40 nm). In addition, by using the inclusion properties of cyclodextrin, these glyconanoparticles were successfully post-functionalized using a water-soluble redox compound, such as anthraquinone sulfonate (AQS) and characterized by cyclic voltammetry. The resulting glyconanoparticles exhibit the classical electroactivity of free AQS in solution. The amount of AQS immobilized by host–guest interactions is proportional to the percentage of polystyrene-block...

Research paper thumbnail of Wearable Biosupercapacitor: Harvesting and Storing Energy from Sweat

Advanced Functional Materials

Research paper thumbnail of Stretchable and Flexible Buckypaper‐Based Lactate Biofuel Cell for Wearable Electronics

Advanced Functional Materials

Research paper thumbnail of Comparison of Commercial and Lab-made MWCNT Buckypaper: Physicochemical Properties and Bioelectrocatalytic O2 Reduction

Research paper thumbnail of Buckypaper bioelectrodes: emerging materials for implantable and wearable biofuel cells

Energy & Environmental Science

Carbon nanotubes (CNTs) have been widely exploited for the development of enzymatic biofuel cells... more Carbon nanotubes (CNTs) have been widely exploited for the development of enzymatic biofuel cells with sufficient power densities in the μW to mW range for operating low-power bioelectronic devices from renewable substrates.

Research paper thumbnail of DNA-Mediated Nanoscale Metal-Organic Frameworks for Ultrasensitive Photoelectrochemical Enzyme-Free Immunoassay

Analytical chemistry, Jan 20, 2018

A novel enzyme-free photoelectrochemical (PEC) immunoassay was developed for the ultrasensitive d... more A novel enzyme-free photoelectrochemical (PEC) immunoassay was developed for the ultrasensitive detection of prostate specific antigen (PSA) based on the DNA-mediated nanoscale zirconium-porphyrin MOFs (NMOFs). By virtue of the intrinsic coordination between unsaturated zirconium sites of the NMOFs frameworks and phosphonate groups, the 5'-phosphorylared ss-DNA-tagged antibody (Ab-DNA) conjugate with a consecutive stretch of guanines as a spacer could be loaded on the NMOFs easily, obtaining a novel type of Ab-DNA-functionalized NMOFs complex. Additionally, as a photocathode PEC active nanomaterial, NMOFs exhibited a significant enhanced photocurrent response with the presence of dopamine under oxygen-containing aqueous media at -0.3 V (vs Ag/AgCl). Furthermore, with the aid of the electrochemical grafting of polyamidoamine (PAMAM) dendrimers functionalized interface, the novel type of Ab-DNA-NMOFs further served as PEC signal nanoprobe for the ultrasensitive PSA immunoassay. Un...

Research paper thumbnail of Dawson-type polyoxometalate nanoclusters confined in a carbon nanotube matrix as efficient redox mediators for enzymatic glucose biofuel cell anodes and glucose biosensors

Biosensors & bioelectronics, Jan 30, 2018

Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (CHN)[PMoO]·4H... more Two new inorganic-organic hybrid materials based on heteropolyoxometalates (POMs): (CHN)[PMoO]·4HO (PMo) and (CHNO)[HPWO]·6HO (PW) are reported as mediators for electron transfer between FAD-dependent glucose dehydrogenase (FAD-GDH) and a multiwalled carbon nanotube (MWCNT) matrix for glucose biofuel cell and biosensor applications. These polyoxometalates were chosen due to their promising redox behavior in a potential range for mediated electron transfer with the glucose oxidizing enzyme, FAD-GDH. PMo and PW were immobilized on 1-pyrenemethylamine (PMA) functionalized MWCNT deposits. After immobilization of FAD-GDH, the PW-modified MWCNT electrode demonstrated mediated electron transfer and provided a catalytic current density of 0.34 mA cm at 0.2 V vs SCE with an open circuit potential (OCP) of -0.08 V vs SCE. A 10-fold increase in catalytic current to 4.7 mA cm at 0.2 V vs SCE and a slightly lower OCP of -0.10 V vs SCE was observed for an equivalent electrode modified with PMo.Th...

Research paper thumbnail of Redox-Active Glyconanoparticles as Electron Shuttles for Mediated Electron Transfer with Bilirubin Oxidase in Solution

Journal of the American Chemical Society, Nov 15, 2017

We demonstrate self-assembly, characterization and bioelectrocatalysis of redox-active cyclodextr... more We demonstrate self-assembly, characterization and bioelectrocatalysis of redox-active cyclodextrin-coated nanoparticles. The nanoparticles with host-guest functionality are easy to assemble and permit entrapment of hydrophobic redox molecules in aqueous solution. Bis-pyrene-ABTS encapsulated nanoparticles were investigated electrochemically and spectroscopically. Their use as electron shuttles is demonstrated via an intraelectron transfer chain between neighboring redox units of clustered particles (Dh,DLS = 195 nm) and the mono- and trinuclear Cu sites of bilirubin oxidases. Enhanced current densities for mediated O2 reduction are observed with the redox nanoparticle system compared to equivalent bioelectrode cells with dissolved mediator. Improved catalytic stability over 2 days was also observed with the redox nanoparticles, highlighting a stabilizing effect of the polymeric architecture. Bioinspired nanoparticles as mediators for bioelectrocatalysis promises to be valuable for ...

Research paper thumbnail of Electrocatalytic oxidation of alcohols on carbon electrodes modified by functionalized polypyrrole–RuO2 films

Journal of Molecular Catalysis

The electrocatalytic activity of several types of polypyrrole films bearing cationic pendant grou... more The electrocatalytic activity of several types of polypyrrole films bearing cationic pendant group [tris@ipyridyl)ruthenium(II) complexes, viologen, ammonium] and containing dispersed microparticles of RuOe towards the oxidation of alcohols to aldehydes or ketones has been investigated. Best results are obtained with polypyrrole films substituted by a tris(bipyridyl)ruthenium(II) complex, the latter acting as an electron relay for the electrogeneration of the strong oxidizing species RuOz-. The influence of several parameters such as base, supporting electrolyte, electrolysis potential and catalyst amount on the efficiency of the electrocatalysis has been examined. Under optimum conditions a maximum turnover of 10 900 was reached. In all cases the lifetime of these electrode materials was limited by the slow release of the RuO:-species.

Research paper thumbnail of A High Power Buckypaper Biofuel Cell: Exploiting 1,10-Phenanthroline-5,6-dione with FAD-Dependent Dehydrogenase for Catalytically-Powerful Glucose Oxidation

Research paper thumbnail of Graphene/clay composite electrode formed by exfoliating graphite with Laponite for simultaneous determination of ascorbic acid, dopamine, and uric acid

Monatshefte für Chemie - Chemical Monthly

ABSTRACT Laponite/graphene composite (Lap/G) was prepared by directly exfoliating graphite with L... more ABSTRACT Laponite/graphene composite (Lap/G) was prepared by directly exfoliating graphite with Laponite under mechanical grinding. The morphologies and intrinsic physical properties of Lap/G were characterized by transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy. Electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry were used to investigate the electrochemical behavior of Lap/G-modified electrodes. The resulting Lap/G composite exhibited good electroconductivity combined with electrocatalytic activity towards oxidation of small biomolecules such as dopamine. Furthermore, the resulting Lap/G-modified glassy carbon electrodes were applied for simultaneous determination of ascorbic acid, dopamine, and uric acid.

Research paper thumbnail of Towards a Versatile Photoreactive Platform for Biosensing Applications

Journal of Analysis and Testing

An original interfacial hybrid cross-linker molecule combined electrochemical and photochemical p... more An original interfacial hybrid cross-linker molecule combined electrochemical and photochemical properties by substitution of two functional groups, pyrene, and diazirine. The first group enables anchoring by strong p-stacking interaction or by electropolymerization onto multi-walled carbon nanotubes (MWCNT). The other photoreactive group allows the covalent link with biomolecules under long-wavelength UV illumination. Diazirine was chosen due to its ability to photogenerate high reactive radicals under UV irradiation. The photoreactivity of these immobilized nanostructured conductive surfaces was tested towards the covalent attachment of tyrosinase which is well known to oxidize a large range of phenolic compounds and its yield and availability was evaluated by amperometric measurements of catechol by using molecular dioxygen. The architecture exhibiting the best analytical characteristics obtained for catechol was then chosen to detect dopamine.

Research paper thumbnail of Zirconium-Based Porphyrinic Metal-Organic Framework (PCN-222): Enhanced Photoelectrochemical Response and Its Application for Label-Free Phosphoprotein Detection

Analytical chemistry, Jan 15, 2016

A simple and rapid photoelectrochemical (PEC) sensor was developed for the label-free detection o... more A simple and rapid photoelectrochemical (PEC) sensor was developed for the label-free detection of a phosphoprotein (α-casein) based on a zirconium based porphyrinic metal-organic framework (MOF), PCN-222, which exhibited an enhanced photocurrent response toward dopamine under the O2-saturated aqueous media. In this work, in terms of PEC measurements and cyclic voltammetry, the PEC behaviors of PCN-222 in aqueous media were thoroughly investigated for the first time. Additionally, in the virtue of the steric hindrance effect from the coordination of the phosphate groups and inorganic Zr-O clusters as binding sites in PCN-222, this biosensor showed high sensitivity for detecting α-casein and the limit of detection (LOD) was estimated to be 0.13 μg mL(-1). Moreover, the proposed method provides a promising platform for clinic diagnostic and therapeutics.

Research paper thumbnail of Synergetic Effects of Combined Nanomaterials for Biosensing Applications

Sensors (Basel, Switzerland), Jan 3, 2017

Nanomaterials have become essential components for the development of biosensors since such nanos... more Nanomaterials have become essential components for the development of biosensors since such nanosized compounds were shown to clearly increase the analytical performance. The improvements are mainly related to an increased surface area, thus providing an enhanced accessibility for the analyte, the compound to be detected, to the receptor unit, the sensing element. Nanomaterials can also add value to biosensor devices due to their intrinsic physical or chemical properties and can even act as transducers for the signal capture. Among the vast amount of examples where nanomaterials demonstrate their superiority to bulk materials, the combination of different nano-objects with different characteristics can create phenomena which contribute to new or improved signal capture setups. These phenomena and their utility in biosensor devices are summarized in a non-exhaustive way where the principles behind these synergetic effects are emphasized.

Research paper thumbnail of In situ formed copper nanoparticles templated by TdT-mediated DNA for enhanced SPR sensor-based DNA assay

Biosensors & bioelectronics, Jan 15, 2017

For the efficient surface plasmon resonance (SPR)-based DNA assay researching, signal amplificati... more For the efficient surface plasmon resonance (SPR)-based DNA assay researching, signal amplification tactics were absolutely necessary. In this work, a sensitive SPR-DNA sensor was developed by employing in situ synthesis of copper nanoparticles (CuNPs) templated by poly-T sequences DNA from terminal deoxynucleotidyl transferase (TdT)-mediated extension, and synergistically with nano-effect deposition as the mass relay. The objective of this strategy was manifold: firstly, tDNA hybridized with the optimal designed probes to active the TdT-mediated DNA extension onto the surface of SPR chip, resulted a long poly-T sequences ssDNA chain in dsDNA terminal onto surface of gold chip and characterized by SPR signal amplitudes. Secondly, copper ion (Cu(2+)) adsorbed into the skeleton of poly-T sequences DNA, with the aid of ascorbic acid (VC) to achieve the Cu(2+) reduction, copper nanostructures (CuNPs) was synchronously generated onto the single nucleotide chain anchoring in dsDNA derivat...

Research paper thumbnail of Enhanced Electrochemiluminescence of One-Dimensional Self-Assembled Porphyrin Hexagonal Nanoprisms

ACS applied materials & interfaces, Jan 21, 2017

In this work, we synthesized the one-dimensional nanostructure of zinc 5,10,15,20-tetra(4-pyridyl... more In this work, we synthesized the one-dimensional nanostructure of zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP) via a self-assembly technique. Using sodium dodecyl sulfate (SDS) as "soft template", the self-assembled ZnTPyP (SA-ZnTPyP) had the morphology of hexagonal nanoprisms with a uniform size (diameter of 100 nm). The SA-ZnTPyP exhibited remarkably different spectral properties compared to those of the original ZnTPyP. The as-prepared SA-ZnTPyP was used to modify glassy carbon electrodes (GCE), and the electrochemiluminescence (ECL) behaviors of the SA-ZnTPyP/GCE were investigated. The hydrophilic carbon dots (C-dots) could efficiently prevent the dissolution of SA-ZnTPyP in DMF containing 0.1 mol L(-1) TBAP and, simultaneously, could accelerate electron transfer. Therefore, the enhanced ECL was realized by C-dots/SA-ZnTPyP/GCE by using H2O2 as co-reactant. This amplification of ECL was further studied by ECL spectroscopies and cyclic voltammetry, and the...

Research paper thumbnail of Controlled carbon nanotube layers for impedimetric immunosensors: High performance label free detection and quantification of anti-cholera toxin antibody

Biosensors & bioelectronics, Jan 15, 2017

An original impedimetric immunosensor was developed based on carbon nanotube (CNT) deposits with ... more An original impedimetric immunosensor was developed based on carbon nanotube (CNT) deposits with controlled thicknesses for enhanced electroactive surface areas leading to improved sensor performances. Cholera monitoring was chosen as the model immune system for this setup. These CNT deposits were characterized using confocal laser microscopy and electrochemical methods. To form the sensor device, the CNT deposits were functionalized via electrocoating of polypyrrole-nitrilotriacetic acid (poly(pyrrole-NTA)) followed by the formation of a Cu (II) complex with the NTA functions. The bioreceptor unit, cholera toxin B Subunit, modified with biotin, was then immobilized via coordination of the biotin groups with the NTA-Cu(II) complex. Each step of the formation of the immunosensor and the subsequent binding of the analyte antibody anti-cholera toxin were investigated with cyclic voltammetry and Electrochemical Impedance Spectroscopy. After optimization, the resulting impedimetric chole...

Research paper thumbnail of Assembly and Stacking of Flow-through Enzymatic Bioelectrodes for High Power Glucose Fuel Cells

ACS applied materials & interfaces, Jan 19, 2017

Bioelectrocatalytic carbon nanotube based pellets comprising redox enzymes were directly integrat... more Bioelectrocatalytic carbon nanotube based pellets comprising redox enzymes were directly integrated in a newly conceived flow-through fuel cell. Porous electrodes and a separating cellulose membrane were housed in a glucose/oxygen biofuel cell design with inlets and outlets allowing the flow of electrolyte through the entire fuel cell. Different flow setups were tested and the optimized single cell setup, exploiting only 5 mmol L(-1) glucose, showed an open circuit voltage (OCV) of 0.663 V and provided 1.03 ± 0.05 mW at 0.34 V. Furthermore, different charge/discharge cycles at 500 Ω and 3 kΩ were applied to optimize long-term stability leading to 3.6 J (1 mW h) of produced electrical energy after 48 h. Under continuous discharge at 6 kΩ, about 0.7 mW h could be produced after a 24 h period. The biofuel cell design further allows a convenient assembly of several glucose biofuel cells in reduced volumes and their connection in parallel or in series. The configuration of two biofuel ce...