Dual-strategy molecularly imprinted electrochemical sensors for ultrasensitive and green determination of Tenoxicam: Electropolymerization vs Photopolymerization

Tenoxicam (TNX) is a widely used non-steroidal anti-inflammatory drug, and its determination in pharmaceutical, biological, and environmental samples requires sensitive and selective analytical methods. In this study, two molecularly imprinted polymer (MIP)-based electrochemical sensors were developed for the trace-level detection of TNX. The imprinted polymer films were fabricated directly on glassy carbon electrodes (GCEs) using two different polymerization strategies: electropolymerization (EP-TNX@MIP/GCE) and photopolymerization (PP-TNX@MIP/GCE). The sensors were characterized using scanning electron microscopy (SEM), ATR-FTIR spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), confirming the successful formation of selective recognition sites. Under optimized conditions, differential pulse voltammetry (DPV) measurements showed a linear detection range of 1 × 10⁻¹²–1 × 10⁻¹¹ M for both sensors. The limits of detection were 5.65 × 10⁻¹³ M for EP-TNX@MIP/GCE and 7.68 × 10⁻¹³ M for PP-TNX@MIP/GCE, indicating high analytical sensitivity compared with previously reported TNX sensing methods. The developed sensors also showed high selectivity for TNX over structurally related drugs. Satisfactory recovery values ranging from 95.18% to 103.17% were achieved in pharmaceutical formulations, human serum, tap water, and soil samples. Furthermore, the environmental sustainability of the proposed method was assessed using the BAGI, AGREE, and AGREEMIP metrics, demonstrating strong adherence to green analytical chemistry principles. While further research into long-term stability and wider environmental effects is needed, the results indicate that the proposed MIP-based electrochemical sensors offer a straightforward, sensitive, and sustainable method for detecting TNX in complex matrices.