Electrochemically polymerized composites of conducting poly(p-ABSA) and flavins (FAD, FMN, RF) films and their use as electrochemical sensors:: A new potent electroanalysis of NADH and NAD+

We report the preparation and characterization of poly(p-aminobenzene sulfonic acid) (PABS) films doped with flavins (flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), riboflavin (RF)). It is noted as PABS/flavins modified electrodes. In this study, the conducting polymer, PABS served as a matrix during the electropolymerization to synthesize PABS/flavin composite films. The synthetic, morphological and electrochemical properties of PABS/flavin films and PABS films were compared. Characterization was performed by cyclic voltammetry (CV), atomic force microscopy (AFM), scanning electron microscopy (SEM) and ultraviolet visible (UV-vis) spectroscopy. AFM and SEM images revealed that the incorporation of flavins significantly altered the morphology of the PABS films. UV-vis spectroscopy confirmed the presence of flavins within composite films. PABS/FAD composite modified glassy carbon electrode (PABS/FAD/GCE) is used to electrochemically detect NADH and NAD(+). PABS/FAD/GCE showed excellent electrocatalytic activity for the oxidation of NADH and for the reduction of NAD(+). At optimum conditions, the sensor has a fast response to NADH and a good linear response observed for NADH in the range from 10 to 300 mu M. The cyclic voltammograms (CVs) waves of nicotinamide adenine dinucleotide reduction -oxidation (NAD(+)/NADH) reversible reaction was also observed. (C) 2006 Elsevier B.V. All rights reserved.