Evaluation of the selective detection of 4,6-dinitro-o-cresol by a molecularly imprinted polymer based microsensor electrosynthesized in a semiorganic media

A carbon fiber microelectrode (CFME) was coated with a polymeric film, in order to synthesize an MIP based voltammetric microsensor for the selective determination of DNOC. The polymeric synthesis was carried out by electrocopolymerization of aniline and o-phenylenediamine (o-PD) in a water:methanol (1: 1) media. The response of the MIP-sensor synthesized to the target analyte, was linear in a range from 8 x 10(-7) to 10(-4) M with a sensitivity of 1.6 x 10(3) nA M-1 and good stability and repeatability (< 14%). Different rebinding experiments were carried out in order to evaluate the binding properties of the MIP-sensor. The experimental adsorption isotherms were fitted to Langmuir, Bi-Langmuir and Freundlich-Langmuir isotherms and the Langnmir model was chosen as the best fitting model. Under the optimized experimental conditions, the voltammetric microsensor was able to differentiate between DNOC and other closely related compounds such as other dinitrophenolic pesticides like binapacryl or dinobuton. (c) 2007 Elsevier B.V. All rights reserved.