Highly sensitive non-enzymatic electrochemical sensor for uric acid detection using copper oxide nanopebbles-modified glassy carbon electrode

A highly sensitive mediator-dependent electrochemical non-enzymatic biosensor for uric acid sensing was developed using copper oxide nanopebbles as an effective electrochemical sensing platform. For this purpose, CuO nanopebbles were prepared using a simple wet chemical route and employed to fabricate CuO-modified glass carbon (GC) electrode with chitosan as a binder to form GC/CuO/Chitosan. The electrochemical oxidation and reduction of uric acid at the electrode-electrolyte interface were facilitated by the electrocatalytic behaviour of CuO nanopebbles. Upon employing differential pulse voltammetry, the fabricated electrode detected uric acid over a broad linear range of 0.1-1.2 mM with a high sensitivity of 0.020 mu A mu M- 1 and a low limit of detection of 28.2 nM. The developed electrode offers high stability over a period of 14 days with good repeatability (1.61 % RSD) and reproducibility (2.27 % RSD). Finally, the fabricated electrode was tested to quantify the spiked uric acid concentrations in synthetic urine samples to analyse the practical ability of the electrode in real-world analysis, and the recovery results (99.4-100.7 %) were satisfactory. Taken together, the fabricated CuO nanopebble-based GC electrode could be used as a promising candidate for sensing and quantifying ultra-low levels of uric acid in urine samples.