Electrochemical detection of chloramphenicol using gadolinium tungstate with sulphur-doped carbon nitride...

Chloramphenicol (CAP) is a broad-spectrum antibiotic whose unregulated presence in pharmaceuticals and food products raises significant health concerns, underscoring the need for rapid, reliable detection methods. This study aimed to develop a sensitive and economical electrochemical sensing platform based on a novel gadolinium tungstate (Gd₂(WO₄)₃) and sulphur-doped graphitic carbon nitride (S-g-C₃N₄) nanocomposite for the efficient determination of CAP.

The Gd₂(WO₄)₃/S-g-C₃N₄ nanocomposite was synthesized via a simple co-precipitation method and characterized using XRD, XPS, EDS, and TEM to confirm structural and morphological integration. A glassy carbon electrode modified with the composite was evaluated by cyclic and linear sweep voltammetry, along with analyses of interference, repeatability, stability, and real samples in eye-drop formulations and milk.

The modified electrode exhibited significantly enhanced electrocatalytic oxidation of CAP compared with bare and individually modified electrodes, demonstrating high sensitivity, good selectivity against common interferents, and strong operational stability and reproducibility. A low detection limit was achieved, and the electrode effectively quantified CAP in real matrices with satisfactory recovery.

The findings establish the Gd₂(WO₄)₃/S-g-C₃N₄ nanocomposite as an efficient sensing material, offering a reliable, stable, and cost-effective platform for routine monitoring of antibiotic residues. While minor optimization may further expand its applicability, the study advances electrochemical sensing by introducing a robust nanocomposite with improved analytical performance for CAP detection.