A Hydrogen Peroxide Biosensor Based on Room Temperature Ionic Liquid Functionalized Graphene Modified Carbon Ceramic Electrode

Abstract

Abstract A room temperature ionic liquid (IL) 1‐butyl‐3‐methylimidazolium hexafluorophosphate functionalized graphene (GE) was prepared and a hydrogen peroxide (H 2 O 2 ) biosensor was fabricated by immobilizing hemoglobin (Hb) into the IL‐GE composite film. UV‐visible and Fourier transform infrared spectra of the composite film indicated that Hb retained its native structure in the film. Electrochemical investigation of the biosensor showed a pair of well‐defined, quasi‐reversible redox peaks with E pa =−0.209 V and E pc = −0.302 V (vs. SCE) in pH 7.0 phosphate buffer solution at the scan rate of 100 mV/s. To the reduction of H 2 O 2 , the biosensor had a good linear range from 8.0×10 −7 to 1.8×10 −4 mol/L with a detection limit of 3.0×10 −7 mol/L. The apparent Michaelis‐Menten constant K app M was estimated to be 3.4×10 −5 mol/L.