Electrochemical sensor using methimazole imprinted polymer sensitized with MWCNTs and Salen-Co(III) as recognition element

Abstract

This study describes the development of a sensor with molecularly imprinted polymer (MIP) sensitized with MWCNTs and Salen-Co(III) as recognition element for methimazole (MMI) determination. This is the first report of MWCNTs and Salen-Co(III) in MIP being used to enhance its conductivity and catalytic activity in the electrochemical oxidation process. The electrocatalytic mechanism of MMI was explained in detail by evaluating the obtained voltammograms at various potential sweep rates and pH of buffer solutions. A stable, sensitive analytical method of differential pulse voltammetry (DPV) was developed using the prepared MWCNTs-Salen-Co(III)-MIP electrode for the determination of amounts of MMI, resulting in a linear range of 0.5-6.0 mg L(-1) with detection limit of 0.048 mg L(-1). It was also successfully applied for MMI determination in tablets and spiked urine sample. At three concentration levels, the recoveries for two samples were achieved to 94.0-100.1% and 87.8-101.8%, respectively. Analytical reproducibility and stability of the developed method were also evaluated by RSD, which were calculated as 4.6-6.6% and 2.0-6.1% (n=3), respectively.