Direct Electrochemistry and Electrocatalysis of Cytochrome C on the Interface of Ionic Liquid Functionalized Nano-Gold

Abstract

A novel reagentless H2O2 biosensor based on ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) functionalized nano-gold as the biocompatible interface of Cytochrome C (Cyt c) by self-assembled method was proposed. The immobilized Cyt c showed direct electrochemistry and displayed an excellent electrocatalytic response to the reduction of H2O2 without the aid of any electron mediator. Under optimal experimental conditions, the as-prepared biosensor showed a wide linear response to H2O2 in the range of 0.23 µM to 3.0 mM with a detection limit of 0.12 µM (S/N = 3). The resulting biosensor can reached 95% of steady-state current within 5 s. The Kappm value for H2O2 was found to be 1.2 mM.