<p>Electrochemical sensors have emerged as a valuable tool for detecting selective and sensitive antioxidants. Chromium oxide (Cr₂O₃) nanoparticles have shown great potential as modifiers for carbon paste electrodes (CPEs), owing to their superior conductivity and favorable electrochemical characteristics. Cr₂O₃ nanoparticles were synthesized by the combustion method using chromium (III) nitrate as oxidizer and glycine as a fuel, with the reaction carried out at 350&#xa0;°C. Their microstructural features are analyzed through techniques of FESEM and XRD. The electroanalytical performance of a modified electrode (PGly/Cr₂O₃/CPE) for antioxidant Rutin (RU) detection was investigated in phosphate buffer solution (PBS, pH 6.6) by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The diffusion-controlled nature of the electrochemical process is confirmed through sweep rate variation studies. Differential pulse voltammetry (DPV) analysis demonstrated a low detection limit of 0.21&#xa0;μM for RU. The modified electrode exhibited outstanding selectivity for interfering ions and achieved an accuracy of 99.83- 111.26% in real sample analysis. The PGly/Cr₂O₃/CPE sensor demonstrated outstanding catalytic activity, along with selectivity, sensitivity, reproducibility, repeatability, and stability for the detection of Rutin (RU).</p> Graphical Abstract <p></p>