Polyphenylenediamine/OH-MWCNTs Nano-composite Based Sulfamethoxazole-MIP Electrochemical Sensor for Analysis of Biological and Pharmaceutical Samples

Molecular Imprinting Technology (MIT) is a technique to design artificial receptors called Molecularly Imprinted Polymers (MIPs). In the two past decades, the preparation of MIPs and their applications have attracted the interest of many research groups with different interests [1]. MIPs were introduced in 1931 [2]. MIPs are synthesized by copolymerization process of the functional monomers and a cross-linking agent in the presence of template molecules. The extraction of template molecules results in creation of cavities with specific binding sites bearing defined shape, size and functional groups for the analyte. These cavities are potential to trap the template selectively from the mixtures containing closely related molecules [3]. In this communication the potential of a sulfamethoxazole-molecularly imprinted polymer, prepared by using polyphenylenediamine, triphenylamine, OH-functionalized multi-walled carbon nanotube (OH-MWCNT) composite for modification of the carbon paste electrode (CPE) to fabricate a selective sulfamethoxazole electrochemical sensor is reported. Electrochemical behavior of sulfamethoxazole on the investigated modified electrode and the optimization of parameters affecting sulfamethoxazole determination by the sensor were studied by using cyclic voltammetry technique. The calibration curve for sulfamethoxazole determination was obtained by incorporating the fabricated sensor as working electrode in differential pulse voltammetry systems. It was confirmed that the anodic peak current increased linearly with the analyte concentration in the range 1.0×10-6–9.0×10-3 mol L-1 with a limit of detection 4.5×10-7 mol L-1. The inter-day and intra-day relative standard deviations of the developed sensor for the determination of 10-4 mol L14th Annual Electrochemistry Seminar of Iran Materials and Energy Research Center (MERC), 12- 13 Dec, 2018 81 1 sulfamethoxazole, were determined as 3.45 and 7.44%, respectively. The selectivity of the proposed sensor was tested by determination of sulfamethoxazole in binary solutions containing sulfamethoxazole/glucose, sulfamethoxazole/lactose and sulfamethoxazole/ascorbic acid. The modified carbon paste electrode was successfully applied for the determination of sulfamethoxazole in some biological and pharmaceutical samples. The reliability of the method was examined by independent analysis of the samples using HPLC.