Electropolymerized molecularly imprinted electrochemical sensor for sensitive and selective detection of an antipsychotic compound chlorpromazine

Abstract

A multi-step fabrication strategy was employed to construct an electrochemical sensor for the selective detection of chlorpromazine hydrochloride (CPZ·HCl), an antipsychotic drug with a narrow therapeutic index. The sensor was developed using a gold-plated glassy carbon electrode, followed by in situ co-electropolymerization of o-phenylenediamine and gold nanoparticles in the presence of CPZ·HCl as a molecular template. The electrode surface was sequentially polished, cleaned, and enhanced with gold deposition, then modified with a nano-molecularly imprinted polymer (nano-MIP) film. After template removal, selective cavities complementary to CPZ·HCl were formed, resulting in a 50 % increase in effective surface area (from 3.6 mm² to 5.5 mm²). The sensor exhibited a dynamic detection range from 100 pM to 1 μM, with a detection limit as low as 150 fM. It demonstrated a rapid response (∼8 min), high selectivity (ΔI ratio >12 against interfering agents), and excellent reproducibility (RSD <5 %). These findings highlight the potential of the nanoMIP sensor as a robust and cost-effective platform for the trace detection of chlorpromazine hydrochloride in clinical and environmental samples.