Efficient Immobilization of Glucose Oxidase on Nanocomposite via Layer-by-Layer Self-Assembly to Construct Bionanomultilayer Films

A reagentless glucose biosensor was constructed based on bionanomultilayer films composed of gold nanoparticles (GNps) wrapping multiwalled carbon nanotubes (MWNTs)-polyethylenimine (PEI) nanocomposite and glucose oxidase (GOD) through layer-by-layer (LBL) assembly. Firstly, a hybrid film of chitosan - Prussian blue (CS-PB) which acted as redox mediator had been prepared through directly electrodeposited on gold electrode. Then the biosensor was fabricated based on reliably electrostatic interaction of the positively charged GNps-MWNTs-PEI nanocomposite and the negatively charged GOD. The GNps-MWNTs-PEI nanocomposite was characterized by UV-vis spectra, transmission electron microscopy (TEM) and energy dispersive X-ray spectrometer (EDX). And the fabricated process and electrochemical behaviors of the biosensor was characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Under the optimal conditions, the biosensor exhibited excellent response performance to glucose in the linear range from 0.004 to 6.2 mM, with a low detection limit of 1.3 μM and a high sensitivity of 382.8 μA mM −1 cm −2 . Moreover, the biosensor showed rapid response, good reproducibility and interference-free of other co-existing electroactive species.