An Ultrasensitive ECL Sensor Based on Conducting Polymer/Electrochemically Reduced Graphene Oxide for Non-Enzymatic H2O2 Detection in Biological Samples

In this paper, we will introduce an enzyme-free solid-state electrochemiluminescent (ECL) sensor for ultrasensitive detection of Hydrogen peroxide (H2O2 ), as a significant molecule in many fundamental biological processes. It was fabricated based on the electro immobilization of poly (Luminol/Aniline) (PLA) nanocomposite on the surface of electrochemically reduced Graphene oxide (ERGO)/CeO2 /GCE modified electrode. We applied electrochemical technique as a controllable, rapid and simple method for the electro copolymerization of Luminol and Aniline and also the electrochemical reduction of graphene oxide (GO). The oxygen functional groups in ERGO were mostly eliminated. The properties of the ERGO/CeO2 /PLA modified electrode were also studied by FE-SEM, Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) methods. Under the optimal conditions, this proposed ECL sensor exhibits high sensitivity and wide linear dynamic range for H2O2 determination from 0.8 pmolL-1 to 8 mmolL-1 with the low detection limit of 0.36 p molL-1 (S/N=3) and RSD 1.89 %. The results demonstrate that this enzyme-free solid-state ECL sensor offers a promising candidate for quantification of H2O2 concentration in biological fluids such as human urineIntroduction