Amperometric Cholesterol Biosensor Using Layer-by-Layer Adsorption Technique on Polyaniline-coated Polyester Films

Abstract

An amperometric cholesterol biosensor was fabricated using polyaniline-coated polyester films. Polyaniline was dissolved in chloroform with camphorsulfonic acid, and polystyrene was added to this solution. Using this mixed solution, the coating was placed onto polyester films. Cholesterol oxidase was immobilized onto these films using an electrostatic layer-by-layer adsorption technique. Poly(diallyldimethylammonium chloride) was used as the counter ion source. The level of adsorption was examined and evidence of layer-by-layer adsorption was investigated using a quartz crystal microbalance (QCM). A cholesterol biosensor was fabricated from these films as a working electrode, and it was used to measure the cholesterol concentration.