▎ 摘　　要

In this work, we report an electrochemical cholesterol biosensor based on cholesterol oxidase(ChOx) enzyme immobilized on TiO2- nanoparticles - reduced graphene oxide(rGO) - polypyrrole (PPy) nanocomposite modified electrode.The electrochemical properties of GCE modified PPy (PPy-GCE) were studied using CV (Cyclic Vol-tammetry) and DPV (Differential Pulse Voltammetry). The developed sensor exhibited piecewise linearity from 0.1 mu M to 1 mu M and from 1 mu M to 600 mu M with the sensitivity of 61.665 and 0.1466 (2 mA mM x cm) respectively. The limit of detection of the sensor was found to be 32 nm.