Development of an Electrochemical Sensor Modified With MWCNT-Cooh and Mip for Detection of Diuron

Abstract

A B S T R A C TAn electrochemical sensor modified with a molecularly imprinted polymer (MIP) and carboxylfunctionalized multi-walled carbon nanotubes (MWCNT-COOH) was developed for the sensitive and selective detection of diuron in river water samples. An MIP was obtained by bulk polymerization using the best monomer (methacrylic acid) selected by computational simulation. The surface characteristics of the MIP and NIP (control polymer) samples were evaluated by means of surface area and pore volume determinations, using the BET method. The adsorption efficiency of the MIP was determined in adsorption tests that revealed high adsorption, relative to the control polymer. In addition, MWCNTs functionalized with carboxyl groups were used to enhance the performance of the sensor. Electrochemical studies of diuron using the MIP and MWCNT-COOH immobilized on a carbon paste electrode were performed with wave square voltammetry (SWV). The analytical parameters pH, buffer composition, and amounts of MWCNT-COOH and MIP were investigated and optimized. Excellent results were obtained with a linear range of between 5.2 Â 10 À8 and 1.25 Â 10 À6 mol L À1 , detection limit of 9.0 Â 10 À9 mol L À1 , and sensitivity of 5.1 Â10 5 mA L mol À1 . The MWCNT-COOH-MIP/CPE showed an enhanced electrochemical response, with sensitivity 7.9-fold greater than for a plain carbon paste electrode (CPE). Application of the sensor using river water samples resulted in recoveries between 96.1 and 99.5% and RSD <5% (n=3), demonstrating the reliability of this device.

Synthesis of a new magnetic-MIP for the selective detection of 1-chloro-2,4-dinitrobenzene, a highly allergenic compound

“…In recent years, our research group has worked on the development of highly efficient molecularly imprinted polymers (MIPs) for various analytes [19][20][21][22], in order to obtain selective and specific materials for the extraction of analytes present at very low concentrations [23][24]. These materials with artificially generated recognition sites are capable of rebinding a target molecule with high selectivity, due to the formation of specific binding sites with shape and functionalities complementary to the analyte [24], acting similarly to natural receptors with antibody-antigen interactions.…”

Synthesis and characterization of magnetic-molecularly imprinted polymers for the HPLC-UV analysis of ametryn

“…According to the results, obtained from experimental design, the optimum molar ratio of T-FM-BM is 1:4.49:22.48. Thus, the mag-MIP in this work was synthetized using the proportion 1:4:20, which is a rounding to the optimum proportion proposed by Koohpaei et al [41,42], it is also a common proportion in literature [43].…”

Tailoring of nanostructured material as an electrochemical sensor and sorbent for toxic Cd(II) ions from various real samples

“…Factors which affect the adsorption such as template-monomer ratio (Waalkes 2003;Wei et al 2012;Rezaei and Rahmanian 2011;Mhammedi et al 2009), effect of mass, and effect of solvent were also determined. Reusability studies were carried out by adsorption desorption experiment (Wong et al 2015). Swelling studies were carried out, and EWC% (equilibrium water content) was calculated by the below Eq.…”

“…The presence of metal ions causes the alteration of current, potential which can be used for the sensing of metal ions. Voltammetric method is used for this sensing because of their intrinsic specificity, fast response, low cost, and soaring sensitivity and due to the short analysis time (Wong et al 2015;Lee et al 2016a).…”