Development of a new highly sensitive electrochemical sensor to piroxicam anti-inflammatory determination using a disposable screen-printed electrode

In this study, a novel analytical method was developed for determining piroxicam, employing a modified screen-printed carbon electrochemical sensor. This sensor utilizes a nanomaterial composed of reduced graphene oxide with antimony nanoparticles (rGO-SbNPs), which was characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and electrochemical methods. The rGO-SbNPs demonstrated a significant synergistic effect on the sensor’s performance. Utilizing the cyclic voltammetry technique, the analyte was found to oxidize irreversibly around + 0.30 V. Employing differential pulse voltammetry, the sensor exhibited a broad linear range from 0.808 to 130.0 µmol L⁻¹, with a detection limit of 0.0201 µmol L⁻¹ — the lowest reported for piroxicam on screen-printed carbon electrodes in the literature — and a quantification limit of 0.0610 µmol L⁻¹. It also demonstrated good reproducibility, evidenced by a relative standard deviation of 4.66%. Additionally, the sensor showed high selectivity for the analyte even in the presence of various compounds and ions such as flunixin meglumine, ascorbic acid, glucose, lactose, galactose, Ca²⁺, Cl⁻, and Na⁺. The device was successfully applied to tap water and bovine milk samples, yielding satisfactory recoveries: 106.0, 104.0, and 101.0% for water, and 89.9, 97.4, and 93.7% for milk.