Utilizing CuO nanostructures derived from sugar molasses for the detection of xanthine

This study developed a non-enzymatic electrochemical sensor for measuring xanthine using CuO nanostructures made from sugar molasses. The influence of sugar molasses on the surface morphology, crystallization, and optical properties of CuO nanostructures have been investigated during low-temperature aqueous chemical growth method. The influence of different amounts of sugar molasses such as 1 mL (sample 1) and 2 mL (sample 2) on the shape, optical, and crystalline properties of CuO nanostructures was evaluated. The monoclinic phase of sugar molasses CuO nanostructures was confirmed and heterogeneity in the shape orientation was also observed. The optical characterization has revealed a decrease in the optical band gap from 3.36 eV, 2.90 eV, and 2.36 eV for the pure CuO, sample 1, and sample 2, respectively. The proposed CuO nanostructures were found highly active toward electrochemical non-enzymatic detection of xanthine in phosphate buffer solution of pH 7.0. The CuO nanostructures prepared with 1 mL of sugar molasses (sample 1) were observed highly efficient toward non-enzymatic xanthine detection and dynamic linear ranges for various xanthine concentrations were estimated using cyclic voltammetry (CV) and chronoamperometry (CA). Both CV and CA have revealed the dynamic linear range of proposed xanthine sensor from 0.0001 to 0.01 mM and a limit of detection (LOD) of 0.00001 mM. The presented xanthine sensor was evaluated by different sensor evaluation parameters such as selectivity, stability, reproducibility, and the observed performance of sensor was found highly satisfactory. The CuO nanostructures prepared with sugar molasses (sample 1) has shown improved performance due to its high number of active sites, its favorable morphology, its tunable optical band gap, and its fast charge transfer rate at the interface. The CuO nanostructures (sample 1) exhibited charge transfer resistance of 7.72 Ohms and electrochemical active surface area of 0.00202 µF cm⁻². Significantly, CV experiments were conducted under real-life conditions to detect xanthine. Taken together, the combined findings of this work clearly emphasize that sugar molasses-derived CuO nanostructures provide enhanced electrocatalytic properties, thereby offering potential use in diverse biomedical, food, and energy storage-related applications.