Impedimetric mechanism study of horseradish peroxidase at low and high concentrations of hydrogen peroxide based on graphene/sol-gel/horseradish peroxidase

A novel electrochemical modified electrode for the impedimetric mechanism study of horseradish peroxidase and hydrogen peroxide was proposed based on immobilizing horseradish peroxidase/3-(trimethoxysilyl) propylamine/graphene on glassy carbon electrode (HRP/FMSPA/Gr/GCE). Cyclic voltammetry and SEM were utilized to corroborate the successful stepwise assemblage procedure of the electrode. The electrochemical impedance spectroscopy measurements revealed that the charge transfer resistance increases at low concentrations and significantly decreases at high concentrations after enzymatic reaction with hydrogen peroxide. The mechanism study of the horseradish peroxidase and hydrogen peroxide were also investigated by electrochemical impedance spectroscopy. (C) 2018 Elsevier B.V. All rights reserved.