Fabrication of Potentiometric Cholesterol Biosensor by Crosslinking of Cholesterol Oxidase and Carbon Nanotubes Modified Cellulose Acetate Membrane

摘要

The principal objective of this work is to design a novel and improved membranous support for electrochemical sensing of cholesterol by the application of CNT. The present work is based on potentiometric sensing of cholesterol through a cellulose acetate membranous support embedded with a single walled carbon nanotubes (SWNT). Cholesterol Oxidase (ChOx) has been immobilized on the carbon nanotubes mixed cellulose acetate membrane (CA-CNT). Scanning electron microscopic images have shown that cholesterol oxidase is uniformly immobilized over the CA-CNT membrane. The electrocatalytic responses of ChOx/CA-CNT were investigated with various concentration of cholesterol ranging from 10~(-3) M to 10~(-8) M. Compared with ChOx/CA, the ChOx/CA-CNT has better electrocatalytic response to cholesterol. This sensor shows excellent performance with high sensitivity, with a linear range of 10~(-3) M to 10~(-8) M, and a detection limit of 10~(-8) M.