Multivariate optimization of captopril analysis using molecularly imprinted polymer electrochemical nano sensor based on carbon nanotubes

In this project, a novel and selective electrochemical sensor based on molecularly imprinting polypyrrole (MIP) modified with functionalized multi-wall carbon nanotubes (MWCNTs), constructed the captopril (CAP) detection. Three electrochemical techniques, including chronoamperometry, cyclic voltammetry (CV), and differential pulse voltammetry (DPV) were performed in the deposition of MWCNTs on the pencil graphite electrode (PGE) surface, MIP synthesis, and quantitative measurements, respectively. Ten critical parameters were optimized with Placket–Burman design (PBD) and central composite design (CCD) approaches. The field emission scanning electron microscope (FESEM) was used for investigation of the sensor morphology. Under the optimized conditions, the proposed sensor showed a linear range from 20 to 1500 µM with a correlation coefficient (R²) of 0.9901. Furthermore, the limit of detection was obtained 5.0 nM (3Sb/m, n = 3). The electrochemical sensor showed good results for the determination of CAP in pharmaceutical and biological samples.