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

Abstract

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 electroca...