Methylene blue-assisted molecularly-imprinted film modified nitrogen and sulfur co-doped molybdenum carbide for simultaneous electrochemical determination of two hepatotoxic drugs

Abstract

A novel electrochemical sensor with a dual-template molecular imprinting technology was fabricated for the simultaneous detection of paracetamol (PAR) and isoniazid (INZ). The sensor was constructed using nitrogen and sulfur co-doped molybdenum carbide (N, S@Mo₂C) and a thin layer of electro-polymerized methylene blue was applied onto the surface of the N, S@Mo₂C. The electrochemical sensor demonstrated remarkable analytical efficiency for the concurrent PAR and INZ quantification under optimal circumstances. The system achieved an exceptionally low limit of detection (S/N = 3) of 3.7 nM for PAR, with a concentration range of 0.013 and 140 µM. A LOD of 7.6 nM was attained for INZ, with a linear range between 0.025 and 140 µM. Furthermore, the platform's selectivity was evaluated using differential pulse voltammetry (DPV). The designed platform successfully detected PAR and INZ in authentic samples with recoveries varying between 98.3% and 104.9%. The relative standard deviations (RSD) for these measurements ranged from 2.7 to 4.0%, demonstrating that the proposed sensor is extremely stable, repeatable, and reproducible. These promising results suggest that the sensor holds potential for the detection of various (bio) molecules, paving the way for future applications in sensing fields.

Keywords: Differential pulse voltammetry; Isoniazid; Molecularly-imprinted technology; N, S@Mo2C; Paracetamol.