Cholesterol Biosensor Based On Nanoporous Zinc Oxide Modified Electrodes

Abstract

Nanostructured ZnO modified electrodes have been fabricated by co‐electrodeposition with eosin Y onto F‐doped SnO2 (FTO) coated glass, and their application for cholesterol biosensor was studied. For cholesterol application, cholesterol oxidase (ChOx) was immobilized onto the ZnO/FTO electrode via physical adsorption. Cyclic voltammetric measurements showed that the ChOx/ZnO/FTO is sensitive to cholesterol and the optimal solution pH for the ChOx/ZnO/FTO electrode for detecting cholesterol was 6.7. Besides, the redox peak current densities are proportional to the square root of scan rate, or ν1/2, indicating the electron‐transfer process is diffusion limited. The sensitivity, linear detection range, and the limit of detection for the ChOx/ZnO/FTO electrode are 3.01 mA⋅cm2⋅M−1, 1.1∼4.83 mM, and 20 μM, respectively.