Polyaniline Nanofibers: Synthesis, Characterization, and Application to Direct Electron Transfer of Glucose Oxidase

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• 作者：Min Zhao ; Xiuming Wu ; Chenxin Cai*
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：March 26, 2009
• 年：2009
• 卷：113
• 期：12
• 页码：4987-4996
• 全文大小：479K
• 年卷期：v.113,no.12(March 26, 2009)
• ISSN：1932-7455

文摘

Polyaniline nanofibers are synthesized by interfacial polymerization and confirmed by scanning electron microscopy. These nanofibers are characterized by XRD, FTIR, UV−vis spectroscopy, and voltammetry. A detailed study is conducted on the influence of a variety of synthetic conditions on the morphology of the polyaniline nanostructure. These conditions include organic solvents, acid dopants, concentration of dopants, the reaction time, and the concentration of aniline monomer and oxidant. The polyaniline nanofibers are used as an electrode substrate for immobilization and facilitating the direct electron transfer (DET) of redox proteins/enzymes with glucose oxidase (GOx) as a model. After immobilized on the nanofibers, GOx can keep its natural structure and undergoes effective DET reaction with a pair of well-defined, quasi-reversible redox peaks at −418 mV (pH 7.0, 10 mV/s). The apparent electron transfer rate constant is (6.3 ± 1.6) s⁻¹. The GOx-nanoPANI/GC electrode displays good features in electrocatalytic oxidation of glucose; therefore, it can be used as a biosensor for detecting the substrate with a low detection limit (0.5 μM), a wide linear range (0.01 to 1 mM), a low apparent Michaelis−Menten constant (1.05 ± 0.04 mM), and acceptable stability and reproducibility. The good biocompatibility of polyaniline nanofibers enables them to become a simple and effective platform for the integration of proteins/enzymes and electrodes, which can provide analytical access to a large group of enzymes for a variety of bioelectrochemical applications.