Application of carbon nanoparticle/chitosan modified electrode for the square-wave adsorptive anodic striping voltammetric determination of Niclosamide

A new modified electrode formed by carbon nanoparticle/chitosan film (CNP/CS) was used for electrocatalytic reduction of Niclosamide (NA). The electrochemical behavior of NA at the CNP/CS modified electrode was investigated in detail by the means of cyclic voltammetry. The reduction mechanism of NA, corresponds to the redox chemistry of nitro group, was thoroughly investigated. The effect of the experimental parameters e.g. potential and time of accumulation, pH of the buffered solutions and potential sweep rate on the response of the electrode was studied. The prepared electrode showed high stability and uniformity in the composite film, short response time, good reproducibility and an excellent catalytic activity toward the electro-reduction of NA leading to a significant improvement in response sensitivity. The square-wave adsorptive anodic stripping voltammetry (SWAASV) was used as an efficient method for the determination of NA. Under the optimal conditions, the modified electrode showed a wide linear response to the concentration of NA in the range of 0.01-2 mu M with a detection limit of 7.7 nM. The prepared electrode was successfully applied for the determination of NA in pharmaceutical and clinical samples and satisfactory results are obtained. (C) 2009 Elsevier B.V. All rights reserved.