Preparation of zirconia/zinc oxide nanocomposites by sol-gel method for highly sensitive determination of dopamine

A novel electrochemical sensor utilizing ZrO 2 and ZnO hybrid nanocomposites was developed for the specific detection of dopamine (DA) with ultra-high sensitivity and selectivity. The structure and electrochemical properties of the composites were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), a gas adsorption apparatus (BET), and electrochemical analysis. The results indicate that in the ZrO 2 /ZnO nanocomposite, ZrO 2 exhibits a large specific surface area and abundant active sites, which can accelerate the oxidation-reduction reaction of DA. Meanwhile, ZnO nanomaterials demonstrate high electronic conductivity, enhancing the sensor’s adsorption capability for DA. The electrochemical sensor has a detection limit of 94.1 nM within the linear range of 0.5–100 μM. Assays were conducted using human serum samples at physiological pH. The recovery rate was 98.5–101.0%, and the relative standard deviations were less than 5%. This suggests that the electrochemical sensor holds promise for bioanalysis and disease monitoring. Graphical Abstract