A novel nitric oxide biosensor based on electropolymerization poly(toluidine blue) film electrode and its application to nitric oxide released in liver homogenate

A novel poly(toluidine blue)-modified electrode has been constructed for the determination of nitric oxide in biological sample. The electrochemical behavior of poly(toluidine blue) film electrode and its electrocatalytic activity toward NO were studied in detail by cyclic voltammetry. Possible interferences were tested and evaluated after further coated with Nafion. The poly(toluidine blue) and Nafion composite film-modified electrode exhibits a good linear relationship over a NO concentration of 1.8 × 10 −7 to 8.6 × 10 −5 mol/L, and the detection limit is 1.8 × 10 −8 mol/L (S/N = 3). NO release from the rat liver homogenate stimulated by l-arginine was studied, and the responses were decreased by the nitric oxide synthase inhibitor N ω-nitro- l-arginine.