Investigation of electrocatalytic function of Co3O4 flower-like structures and application as uric acid sensor

This investigation evaluates the electrocatalytic property of Co3O4 flower-like structures (CoFS) and its potential application as an amperometric sensor in uric acid (UA) detection. By simple dropcoating method, CoFS were used as a modifier on the glassy carbon electrode (GCE) to fabricate an amperometric sensor. The morphology of the sensor surface was characterised by scanning electron microscope (SEM). The effective surface area of the sensor was calculated by chronocoulometry (CC). The electrocatalytic ability of the sensor to UA oxidation reaction in phosphate buffer solution (pH 7.4) was investigated by cyclic voltammetry (CV) and chronoamperometry. Results suggested that the surface area of the sensor was almost two times larger than that of bare GCE and the CoFS exhibited a strong electrocatalytic activity to the redox reaction of UA. The catalytic peak currents of UA were linearly dependent on the concentrations of UA in the range from 1.0 x 10(-6) to 2.7 x 10(-4) M, with a detection limit of 5.0 x 10(-7) M. The sensor displayed good stability and reproducibility, and it was successfully applied to determine the UA concentrations in human urine samples.