Fabrication of an Electrochemical Biosensor Based on Nafion/Horseradish Peroxidase/Co₃O₄ NP/CILE and Its Electrocatalysis

摘要

This paper focuses on the investigation of direct electrochemistry and electrocatalysis of horseradishperoxidase (HRP) on Co3O4 nanoparticles (NPs) decorated carbon ionic liquid electrode (CILE) as anelectrochemical biosensor for determinations of trichloroacetic acid (TCA) and sodium nitrite(NaNO2). Co3O4 NPs were served to bridge the gaps between electron transport of electrochemicalactive site of HRP to the electrode with the ability to enhance the loading capacity of HRP on theelectrode. Various material characterization techniques such as scanning electron microscopy,transmission electron microscopy, Raman and X-ray photoelectron spectroscopy were used to checkthe structure, morphology and crystal form of Co3O4 NP. Spectroscopic data testified that nodenaturation occurred in the structure of HRP. Electrochemical performances ofNafion/HRP/Co3O4/CILE were conducted in pH 3.0 phosphate buffer solutions, which indicated thatelectron communication was achieved with the appearance of one well-distinct peak couple. Lowdetection limits and wide linear ranges were obtained in electrocatalytic investigations for the differentsubstrates including TCA and NaNO2 with the real samples detected successfully.