Nanostructured zinc oxide platform for cholesterol sensor

Nanostructured zinc oxide (nano-ZnO) film has been fabricated onto indium tin oxide (ITO) containing preferred (002) plane and 10 nm crystallite size using sol-gel technique for immobilization of cholesterol oxidase (ChOx). Electrochemical response of ChOx/nano-ZnO/ITO bioelectrode determined as a function of cholesterol concentration using cyclic voltammetry technique reveals improved detection range (5–400 mg/dl), low detection limit (0.5 mg/dl), fast response time (10 s), sensitivity $(0.059μA/mgdl−1cm−2)$⁠, and low value (0.98 mg/dl) of Michaelis–Menten constant $(Km)$⁠. It is shown that nano-ZnO film provides better environment and enhanced electron transfer between ChOx and electrode.