Electrochemical sensor based on a silver nanowires modified electrode for the determination of cholesterol

Abstract

In this study, the fabrication of an amperometric cholesterol biosensor based on silver nanowires (AgNWs) and cholesterol oxidase (ChOx)–graphene oxide (GO)–chitosan (CS) film is reported. The electrochemical behaviour of the ChOx/Ag/GO/CS/ITO biosensor was studied using cyclic voltammetry (CV), which revealed that the developed biosensor possessed high sensitivity (13.628 μA mM⁻¹ cm⁻²) and a low detection limit (0.427 mg dL⁻¹). The apparent Michaelis–Menten constant, K^app_M, of this biosensor was very low (2.813 mM), originating from the effective immobilization process and the nanowires structure of the substrate. The biosensor expressed a wide linear range up to 400 mg dL⁻¹ in physiological conditions (pH 7.0), making it very promising for the clinical determination of cholesterol.