Application of a nano-structured molecularly imprinted polymer as an efficient modifier for the design of captopril drug selective sensor: Mechanism study and quantitative determination.

In the present study, electrochemical studies and potentiometric determination of captopril (CAP) drug were presented using a glassy carbon electrode (GCE) and carbon paste electrode (CPE), respectively; which is modified with a synthetic nano-structured molecularly imprinted polymer (MIP). CAP-MIP sample with an average particle size of 95 nm was synthesized using a precipitation polymerization method. The electrochemical behavior of CAP was studied on a MIP modified GCE, in an aqueous solution at pH 3.0. The electron transfer coefficient (α) was determined for the CAP drug, using electrochemical approaches. The prepared CAP-MIP was also used as a modifier in a CPE to design a selective CAP sensor, before its potentiometric determination. The modified CPE exhibits a good electrochemical response with a Nernstian slope of 59.15 ± 1.5 mV per decade over a wide linearity in the concentration range of 3.0 × 10-9-1.0 × 10-1 mol L-1. The cyclic voltammetry results were in good agreement with the electrochemical studies for the 1H+/1e- process. The designed electrode indicates a reasonable selectivity for CAP over other studied drugs such as ibuprofen, paracetamol, acyclovir, pyrazinamide, dimenhydrinate, and naproxen as well as with an excellent applicability in some pharmaceutical products.