Amperometric cholesterol biosensor using layer-by-layer adsorption technique onto electrospun polyaniline nanofibers

An amperometric cholesterol biosensor was fabricated using electrospun polyaniline nanofibers. Polyaniline was dissolved in chloroform with camphorsulfonic acid, and polystyrene was added in this solution. Using this mixed solution, nanofibers were formed and collected by electrospinning. Then cholesterol oxidase was immobilized onto these fibers 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) technique. A cholesterol biosensor was fabricated from these nanofibers as a working electrode, and it was used to measure the cholesterol concentration.