Fabrication of Molecularly Imprinted Polymer Coated Carbon Nanotubes Modified Gold Electrode for Determination of Cholesterol

A novel molecularly imprinted polymer (MIP) electrochemical sensor for selective detection of cholesterol has been developed by grafting a very thin polymer film on the surface of the functionalized-carbon nanotube (f-CNT) modified gold electrode. This sensor was made by electropolymerization of 2-mercaptobenzimidazole in the presence of cholesterol as a template on the surface of carbon nanotube modified gold electrode. Since cholesterol did not have any electroactivity on MIP/MWCNT/Au electrode in the phosphate buffer; indirect method was used for the determination of cholesterol. In this method, K3Fe(CN)6/K4Fe(CN)6 redox couples was used as an electrochemical probe to characterize the sensor using cyclic voltammetry, differential pulse voltammetry and chronoamperometry methods. The linear response range for cholesterol detection was between 2 and 350 mg.dL-1 with a detection limit of 1 mg.dL-1. The sensor exhibited good selectivity for cholesterol, with a satisfactory reproducibility and repeatability. The proposed electrode was successfully applied for determination of cholesterol in human blood serum.