▎ 摘　　要

Ultrasensitive detection of antibiotic molecules is fast becoming a vital field of research in recent years. In this research article, we hydrothermally developed a pellet-shaped nanomaterial based on rare-earth metal vanadate (GdVO4) and they are made of composites with graphene oxide (GO). The surface morphology studies through microscopes confirm the effective formation of pellet and sheet-like architectures of GdVO4 and GO. The synthesized nanocomposites are probed for the electrochemical detection of antibiotic sulfadiazine (SLZ). The electrochemical detection performance is investigated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and i-t amperometry analysis. The primary composite of GdVO4 @GO displayed superior selectivity and sensitivity to GdVO4 and GO. Through i-t amperometry analysis, enhanced sensitivity of 1.3009 mu A mu M-1 cm-2 and a limit of detection of 3.1 nM for SLZ detection are achieved. In order to validate the fabricated SLZ sensor, we tested them in real-world biological and environmental samples like human blood serum, river and waste water samples. The GdVO4 @GO-based sensor performed remarkably well with good selectivity for SLZ.