Electrocatalytic evaluation of graphene oxide warped tetragonal t-lanthanum vanadate (GO@LaVO₄) nanocomposites for the voltammetric detection of antifungal and antiprotozoal drug (clioquinol)

Metastable and rarely reported GO warped tetragonal phase t-lanthanum vanadate nanocomposites (GO@LaVO₄-NCs) are reported for the sensitive electrochemical determination of antifungal drug Clioquinol (CQ). The hydrothermal method was adopted for synthesis of GO@LaVO₄-NCs. The electrochemical performance of CQ was examined using cyclic voltammetry (CV) and differential plus voltammetry (DPV) at GO@LaVO₄-NCs modified glassy carbon electrode (GCE). The electrocatalytic oxidation of CQ at the GO@LaVO₄-NCs/GCE shows the highest anodic peak current at a potential of +0.51 V vs. Ag/AgCl. The proposed sensor provides excellent sensitivity of 4.1894 μA μM⁻¹ cm⁻², a very low detection limit (LOD) of 2.44 nM, and a wide range of 25 nM to 438.52 μM towards CQ detection. Finally, the detection of CQ in biological media was successfully done using the GO@LaVO₄-NCs/GCE and possesses recoveries of 94.67–98.0%. Graphical abstract: [Figure not available: see fulltext.]