Computational design of a molecularly imprinted electrochemical sensor for determination of amlodipine via multivariate optimization technique

This study reports the design and evaluation of a new electrochemical sensor based on the molecular imprinting technique to overcome the amlodipine (AML) quantification problems in complex real matrix. In this regard, density functional theory (DFT) calculations [1] were employed to select the most suitable imprinting system for AML quantification technique, which encompassed pyrrol (PY) as functional monomer and water as polymerization solvent. The molecularly imprinted polypyrrole film capable of selectively recognizing AML was successfully synthesized by electropolymerization technique on the pencil graphite electrode (PGE) modified by multi-walled carbon nano-tubes (MWCNTs) [2]. The molecularly imprinted polymer (MIP) film was tested for AML rebinding and differential pulse voltammetry (DPV) was utilized to record the oxidative current signal of AML. Multivariate optimization methods such as Plackett–Burman design (PBD) and central composite design (CCD) were employed to predict the optimum conditions controlling the performance of the MIP sensor. Under optimized conditions (Fig. 1), the MIP electrochemical sensor showed high sensitivity with a linear response from 5 nmol L-1 to 0.2 mmol L-1 of AML and a limit of detection of 1.5 nmol L-1. Moreover, the designed sensor exhibited long-term stability (36 days), good repeatability (RSD 5.3%), reproducibility (RSD 3.4%), and sensitivity toward AML determination in pharmaceutical and human serum samples.