Electrochemical Method for Analysis of Cholesterol Based on In Situ Synthesized Graphene Decorated with Zinc Oxide Nanoparticles

Elli Watanabe
Ryan Spidle, MSU Graduate Student
Steven Caudle, MSU Undergraduate
Geoffrey Manani, MSU Graduate Student
Adam K. Wanekaya, Missouri State University
Amos Mugweru

Abstract

Graphene decorated with zinc oxide nanoparticles were synthesized in a single step. Through this process zinc oxide nanoparticles were deposited onto graphene nanosheets. The nano-composites were characterized using X-ray Diffraction (XRD),Scanning Electron Microscope (SEM), energy dispersive spectroscopy (EDX), cyclic voltammetry and electrochemical impedance spectroscopy. The nanocomposite material displayed excellent catalytic properties toward Cholesterol in combination with cholesterol oxidase (ChOx). The cholesterol detection limit was found to be 5.0 μmol L−1 and a sensitivity 1.3 μA/μM cm2 with linear correlation coefficient R2 = 0.980. The Cholesterol oxidation also followed the Michaelis-Menten kinetics with apparent Km of 46.5 μM