Choline Biosensor Based on Poly(thionine)/H_2O_2 Photoelectrochemical Sensing Interface

A new choline biosensor based on the chitosan immobilized choline oxidase on poly(thionine) modified ITO electrode(PThE) was described.The photosensitive PThE was employed as an electron acceptor,and H2O2 produced by the catalytic reaction was employed as an electron donor.The photoelectrochemical responses of biosensor to H2O2 and choline were studied.The effects of bias voltage,light intensity and pH of electrolyte to photocurrent were investigated.The linear response of choline concentrations ranged from 0.05 to 2.00 mmol/L with a detection limit of 30.0 μmol/L and sensitivity of 65.7 nA/mmol/L.The applied feasibility of the biosensor was acknowledged through monitoring the phosphatidylcholine in lecithin samples.The prepared biosensor is economical,speedy,simple and convenient to detect the choline without hydrogen peroxidase.