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ABSTRACT: A novel amperometric glucose biosensor based on self-assembling glucose oxidase (GOx) and dendrimer-encapsulated Pt nanoparticles (Pt-DENs) on nanofibrous polyaniline (PANI) was described. PANI nanofibers were synthesized via an interfacial polymerization method. A sulfonated polyelectrolytes-poly(sodium 4-styrenesulfonate) (PSS) was used to form the negative PANI/sulfonated polyelectrolyte complex, which had good disperse in aqueous solution. GOx was immobilized on the PANI/PSS surface by alternatively assembling a cationic Pt-DENs layer and an anionic GOx layer. The unique sandwich-like layer structure (Pt-DENs/GOx/Pt-DENs/PANI/PSS) formed by self-assembling provides a favorable microenvironment to keep the bioactivity of GOx and to prevent enzyme molecule leakage. The fabricated Pt-DENs/GOx/Pt-DENs/PANI/PSS electrode exhibited excellent response performance to glucose with a detection limit of 0.5 μM, wide linear range from 10 μM to 4.5 mM, short response time within 5 s, improved sensitivity of 39.63 μA/(mM cm2), and good stability (85% remains after 20 days). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Journal of Applied Polymer Science 04/2008; 109(3):1802 - 1807. · 1.29 Impact Factor
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ABSTRACT: A newly bienzymatic glucose biosensor was prepared for selective and sensitive detection of glucose. This biosensor was built by simultaneous immobilization of glucose oxidase (GOx) and horseradish peroxidase (HRP) into the gold nanoparticles-mesoporous silica composite (GNPs-MPS) matrix, and then casting the composite on glassy carbon electrode (GCE) using Nafion as a cross-linker. Cyclic voltammetry (CV) and amperometry were employed to investigate the catalytic behavior of the biosensor to the oxidation of glucose. As a result, the biosensor exhibited an excellent bioelectrocatalytic response to glucose, as well as good long-term stability and reproducibility.
Nanoelectronics Conference, 2008. INEC 2008. 2nd IEEE International; 04/2008
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ABSTRACT: A novel amperometric biosensor based on self-assembling glutamate dehydrogenase (GLDH) and poly(amidoamine) dendrimer-encapsulated platinum nanoparticles (Pt-PAMAM) onto multiwall carbon nanotubes (CNTs) has been developed for the determination of glutamate. The formation of the self-assembled (GLDH/Pt-PAMAM)(n)/CNTs construction was investigated by zeta-potential and high resolution transmission electron microscopy (HRTEM). The results indicated the uniform growth of the layer-by-layer nanostructures onto carboxyl-functionalized CNTs. The electrocatalytic property of the (GLDH/Pt-PAMAM)(n)/CNTs modified electrode to glutamate in presence of NAD(+) (beta-nicotinamide adenine dinucleotide, 0.1mM) was investigated at a low overpotential 0.2V by electrochemical measurements. The results showed it had series of attractive characteristics, such as a large determination range (0.2-250muM), a short response time (within 3s), a high sensitivity (433muA/mM(-1)cm(2)) and good stability (85% remains after 4 weeks).
Talanta 10/2007; 73(3):438-43. · 3.79 Impact Factor
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ABSTRACT: A type of novel electroanalytical sensing nanobiocomposite material was prepared by electropolymerization of pyrrole containing poly(amidoamine) dendrimers-encapsulated platinum nanoparticles (Pt-PAMAM), and glucose oxidase (GOx). The Pt nanoparticles encapsulated in PAMAM are nearly monodisperse with an average diameter of 3 nm, and they provide electrical conductivity. Polypyrrole acts as a polymer backbone to give stable and homogeneous cast thin films, and it also defines the electrical conductivity. Both Polypyrrole and PAMAM can provide a favorable microenvironment to keep the bioactivity of enzymes such as glucose oxidase. The homogeneity of GOx/Pt-PAMAM-PPy nanobiocomposite films was characterized by atomic force microscopy (AFM). Amperometric biosensors fabricated with these materials were characterized electrochemically using cyclic voltammetry (CV), electrochemical impedance spectra (EIS) and amperometric measurements in the presence of hydrogen peroxide or glucose. All those show the resultant biosensor sensitivity was strongly enhanced within the nanobiocomposite film. The optimized glucose biosensor displayed a sensitivity of 164 μA mM−1 cm−1, a linear range of 0.2 to 600 μM, a detection limit of 10 nM, and a response time of <3 s.
Electroanalysis 06/2007; 19(16):1677 - 1682. · 2.87 Impact Factor
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ABSTRACT: A sensitive enzymed-based biosensor for glucose has been obtained by introducing dendrimer encapsulated Pt nanoparticles via a layer-by-layer assembling method. The free amine groups located on each poly(amidoamine) dendrimer molecule were exploited to covalently attach enzyme to the dendrimer chains using carbodiimide coupling. The resultant enzyme electrodes are shown to have excellent sensitivity (as high as 30.33 μA mM−1 cm−2) and a limit of detection (about 0.1 μmol L−1), depending on metal nanoparticles within dendrimers and the biocompatibility of dendrimers, the linear response range to glucose (from 5 μM to 1.0 mM), a fast response time (within 5 s), and good reproducibility (<8% relative standard deviation between electrodes at low substrate concentration). The sensitivities, and stabilities determined experimentally have demonstrated the potential of dendrimer encapsulated Pt nanoparticles as a novel candidate for enzymatic glucose biosensors.
Electroanalysis 02/2007; 19(6):698 - 703. · 2.87 Impact Factor
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ABSTRACT: A novel amperometric glucose biosensor based on layer-by-layer (LbL) electrostatic adsorption of glucose oxidase (GOx) and dendrimer-encapsulated Pt nanoparticles (Pt-DENs) on multiwalled carbon nanotubes (CNTs) was described. Anionic GOx was immobilized on the negatively charged CNTs surface by alternatively assembling a cationic Pt-DENs layer and an anionic GOx layer. Transmission electron microscopy images and ζ-potentials proved the formation of layer-by-layer nanostructures on carboxyl-functionalized CNTs. LbL technique provided a favorable microenvironment to keep the bioactivity of GOx and prevent enzyme molecule leakage. The excellent electrocatalytic activity of CNTs and Pt-DENs toward H2O2 and special three-dimensional structure of the enzyme electrode resulted in good characteristics such as a low detection limit of 2.5 μM, a wide linear range of 5 μM–0.65 mM, a short response time (within 5 s), and high sensitivity (30.64 μA mM−1 cm−2) and stability (80% remains after 30 days).
Electroanalysis 02/2007; 19(6):717 - 722. · 2.87 Impact Factor
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ABSTRACT: A novel amperometric glucose biosensor based on the nanocomposites of multi-wall carbon nanotubes (CNT) coated with polyaniline (PANI) and dendrimer-encapsulated Pt nanoparticles (Pt-DENs) is prepared. CNT coated with protonated PANI is in situ synthesized and Pt-DENs is absorbed on PANI/CNT composite surface by self-assembly method. Then Glucose oxidase (GOx) is crosslink-immobilizated onto Pt-DENs/PANI/CNT composite film. The results show that the fabricated GOx/Pt-DENs/PANI/CNT electrode exhibits excellent response performance to glucose, such as low detection limit (0.5 µM), wide linear range (1 µM–12 mM), short response time (about 5 s), high sensitivity (42.0 µA mM− 1 cm− 2) and stability (83% remains after 3 weeks).
Materials Science and Engineering: C.
