Sustainable uric acid sensor based on a lab-fabricated electrode modified with rice straw-derived carbon materials

A novel and facile electrochemical sensor for the quantification of uric acid has been fabricated through the strategic modification of a screen-printed carbon electrode (SPCE) using mesoporous carbon-zinc oxide (MC-ZnO) synthesized from rice straw waste. The MC-ZnO materials, generated via a controlled pyrolysis process, exhibit homogeneous dispersion and a substantial electroactive surface area of 0.1286 cm². The electrochemical oxidation of uric acid exhibits a distinct peak at 0.18 V in differential pulse voltammetry (DPV), indicative of efficient charge transfer kinetics. A linear range spanning 20 to 225 µM was obtained with a limit of detection (LOD) of 3.76 µM, signifying exceptional analytical sensitivity. Furthermore, the sensor demonstrates robust selectivity toward uric acid in the presence of typical interferents, underscoring its applicability for precise uric acid determination in complex biological matrices. The sensor's analytical performance was validated by quantifying uric acid in spiked urine samples, yielding recovery rates between 97.9% and 114.8% and relative standard deviations (RSD) below 4.92%, affirming its accuracy and precision. This platform heralds a promising avenue for clinical diagnostics, leveraging sustainable materials for uric acid detection.