A stable and controllable Prussian blue layer electrodeposited on self-assembled monolayers for constructing highly sensitive glucose biosensor

Abstract

A stable and controllable Prussian blue (PB) layer electrodeposited on self-assembled monolayers (SAMs) of thioctic acid amide (T-NH₂) on gold electrode was prepared. The PB, combining with biocompatible matrix chitosan, was used for the highly efficient immobilization of glucose oxidase (GOD) for sensitive biosensing of glucose. The PB on SAMs exhibits a good stability and a much higher catalytic ability toward the reduction of hydrogen peroxide in neutral medium, compared with that of PB directly electrodeposited on bare Au electrode. The biosensor at an applied potential of 0.0 V exhibits good anti-interferent ability, with a low detection limit of 2 μM and a much higher sensitivity (59.9 mA M⁻¹ cm⁻²). The apparent Michaelis–Menten constant (K^app_m) and apparent activation energy of enzymatic reaction were found to be 5.4 mM and 24.1 kJ mol⁻¹. The present method provides a promising platform for the development of new biosensors and bioelectronic devices.