Graphitic carbon nitride-embedded MXene tungsten carbide nanoflakes for sensitive detection of cytotoxic tinidazole in biological samples

Background: Nitroimidazole derivatives, extensively utilized as antibiotics in the pharmaceutical, healthcare, and animal industries, pose a significant environmental threat as potential pollutants. Industrial discharge can introduce these compounds into water sources, where even trace levels of residues, such as tinidazole (TNZ), can adversely affect human health and aquatic ecosystems. However, the electrochemical detection of TNZ remains challenging due to limited sensitivity. Methods: To address this challenge, a novel nanocomposite comprising MXene tungsten carbide (WC) decorated with graphitic carbon nitride nanosheets (WC/gCN NSs) was developed for highly sensitive TNZ detection. The WC/gCN NSs were synthesized through a straightforward approach, yielding stable nanosheets. The WC/gCN NSs-modified electrode demonstrated superior TNZ detection performance compared to conventional methods. This enhancement is attributed to the synergistic interaction between the conductive gCN NSs and the catalytic MXene WC, which generated abundant active sites and facilitated efficient electron transfer. Significant findings: The sensor exhibited exceptional performance, achieving a detection limit of 3.6 nM, high sensitivity (4.2 µA µM⁻¹ cm⁻²), and a recovery rate of 99.9 % (n = 3). It also demonstrated excellent repeatability (RSD 2.4 %), reproducibility, and stability over 30 days. This study provides a promising strategy for designing electrocatalysts with tuneable architectures, contributing to sustainable materials for environmental protection. © 2025 Taiwan Institute of Chemical Engineers