A highly sensitive and selective electrochemical sensor based on computer-aided design of molecularly imprinted polymer for the determination of leflunomide

Abstract

This study includes the electrochemical analysis of leflunomide (LEF), used in the treatment of rheumatoid arthritis, with a molecularly imprinted polymer (MIP) based sensor using different electroanalytical methods. In the design of MIPs, the choice of functional monomer is an important step in terms of the stability of the sensor. Based on the computational approach in this study, ortho-phenylenediamine (o-PD) was chosen as a functional monomer based on the comparison of interaction energies (ΔE) between LEF and monomers, aniline (ANI) was chosen as a platform to develop MIP-based sensor. Morphological characterization of the developed p(ANI-o-PD)@MIP/GCE sensor was performed using Raman spectroscopy, surface electron microscopy (SEM), contact angle measurements, and electrochemical techniques. Quantitative analysis of LEF was performed using differential pulse voltammetry. Results showed that the p(ANI-o-PD)@MIP/GCE sensor has high selectivity and sensitivity. Under optimum conditions, the linear range was found to be 1 – 10 fM (r = 0.998) and the detection limit to be 0.291 fM. Also, the sensor was applied to pharmaceutical dosage form and serum samples to detect LEF, and satisfactory recovery results of 99.46% and 99.15% were obtained. Finally, the p(ANI-o-PD)@MIP/GCE sensor was evaluated using a non-imprinted polymer (NIP)-based electrochemical sensor. The proposed sensor with good reproducibility was effectively implemented for selective and sensitive detection of LEF in pharmaceutical and human serum samples. These results show that the molecular imprinting approach in detecting LEF is a highly effective technique in the potential of the newly developed sensor.