Novel BN-COOH@ZrO<sub>2</sub>/GO Composite for Enhanced\nElectrical Conductivity and Electrochemical Detection of Diclofenac

The\nZrO<sub>2</sub>-embedded carboxy-functionalized <i>h</i>-BN composite, combined with graphene oxide (GO), formed a novel\nBN-COOH@ZrO<sub>2</sub>/GO composite. Structural characterization\nthrough IR, Raman spectroscopy, powder X-ray diffraction, and X-ray\nphotoelectron spectroscopy supported the successful preparation of\nthe composite, while scanning electron microscopy and transmission\nelectron microscopy revealed its surface morphology and the presence\nof component materials. UV–vis spectroscopy (solid state) further\nsupported these findings. Thermogravimetric analysis demonstrated\nenhanced thermal stability of the composite compared to GO. Electrical\nconductivity analysis showed that functionalization alone did not\nimpart significant conductivity to insulating BN. However, integration\nwith GO significantly enhanced conductivity. BN-COOH@ZrO<sub>2</sub>/GO exhibits electrochemical sensor activity for diclofenac sodium\n(DS) detection, achieving a low (limit of detection = 0.0146 μM)\nand high sensitivity (0.2464 μA μM<sup>–1</sup> cm<sup>–2</sup>). The sensor showed high selectivity, reproducibility,\nand stability, effectively detecting DS in real samples with recovery\nrates ranging from 97.69% to 107.21%. This novel composite highlights\nits potential as an efficient material with enhanced thermal stability\nand electrical conductivity for detecting DS through cyclic voltammetry.