Screen-printed electrodes with electropolymerized Meldola Blue as versatile detectors in biosensors

摘要

Electropolymerization of Meldola Blue was carried out by cyclic voltammetry in the range from -0.6 to +1.4 V vs. Ag/AgG, thus defining a new immobilization procedure of the phenoxazine mediator on screen-printed graphite electrodes. Evidence of polymer formation was provided by electrochemical and Fourier transform infrared spectroscopy (FTIR) data. Following polymerization. Meldola Blue preserved the ability to catalyze NADH oxidation allowing to achieve a detection limit of 2.5 x 10(-6) mol l(-1) and a sensitivity of 3713 muA l mol(-1) in amperometric determinations at 0 V vs. Ag/AgCl. In addition, the polymeric mediator was found to facilitate the reduction of hydrogen peroxide in the absence of peroxidase. Typical calibration at -0.1 V vs. Ag/AgCl shows a detection limit of 8.5 x 10(-5) Mol l(-1), a sensitivity of 494 muA I mol and a linear range from 2.5 x 10(-4) to 5 x 10(-3) Mol l(-1) hydrogen peroxide. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 31]