A novel electrochemical sensor based on MIP technology for sensitive determination of cinacalcet hydrochloride in tablet dosage form and serum samples

Cinacalcet hydrochloride (CIN) is a calcium-sensing receptor agonist used to treat hypercalcemia in the parathyroid. The molecularly imprinted polymer (MIP)-based sensor (CIN@MIP/GCE) was electropolymerized using cyclic voltammetry (CV) of the functional monomer o-phenylenediamine (o-PD) with a template molecule CIN on a glassy carbon electrode (GCE). The optimum performance of the MIP-based electrode for CIN detection was obtained with parameters of a 1:7 monomer ratio, a 15-min removal time, ethanol as a removal solution, and a 15-min rebinding time. The surface characterization of the CIN@MIP/GCE sensor was conducted using atomic force microscopy (AFM) and scanning electron microscopy (SEM), while CV and electrochemical impedance spectroscopy (EIS) were employed for electrochemical characterization with [Fe(CN)₆]^3-/^4- redox probe. AFM findings show that the MIP sensor with CIN-specific voids on the surface has a root-mean-square (RMS) value of 27.95, while the non-imprinted polymer (NIP) sensor without voids has a smoother surface formation and an RMS value of 21.30 nm. The analytical efficacy of the constructed sensor was assessed using differential pulse voltammetry (DPV). The limit of detection (LOD) was 0.17 × 10^-12, with a linear range of 1.0 × 10^-12-1.0 × 10^-11 M. The reliability of the constructed sensor was determined using CIN detection in real samples as tablet dosage form and human serum, yielding recovery results of 100.19% and 101.82%, respectively. The selectivity investigation was performed against prevalent interference substances. The relative imprinting factor (IF) values of CIN impurities confirmed the selectivity of the CIN sensor.