Electrochemical ds-DNA-based biosensor decorated with chitosan modified multiwall carbon nanotubes for phenazopyridine biodetection

摘要

A simple and inexpensive method was used to develop a novel electrochemical sensor for the determination of phenazopyridine hydrochloride (PAP). Differential pulse voltammetry was used for the electrochemical investigation of the interaction of PAP with calf thymus ds-DNA at a pencil graphite electrode (PGE) based on the reduced oxidation signals of guanine and adenine. The biosensor was constructed using pretreated pencil graphite electrode (PGE) modified with multiwall carbon nanotubes (MWCNTs) and chitosan (CHIT) decorated with ds-DNA. The reductions in the intensities of guanine and adenine oxidation signals after their interaction with PAP were used as indicators for the sensitive determination of PAP. The differences observed between adenine and guanine oxidation signals (of the ds-DNA) before and after their interaction with PAP were found to be directly proportional to PAP concentration, which was used for quantitative inspections. Under optimum conditions, a linear dependency was observed between guanine and adenine oxidation signals and PAP concentration in the range of 0.01-50 mu g/mL with a detection limit of 0.003 mu g/mL. The method was also found to be highly selective and was successfully employed for the determination of PAP in real samples such as human plasma and urine. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.