Simultaneous and sensitive detection of dopamine and uric acid based on cobalt oxide-decorated graphene oxide composite

Abstract

We demonstrate the simply prepared Co3O4 microsphere-decorated graphene oxide nanosheets (Co3O4/GO) modified electrode towards the single and simultaneous determination of dopamine (DA) and uric acid (UA). Various analytical techniques characterized the physicochemical properties of Co3O4/GO hybrid composite and EIS, CV, and DPV used to analyze the electrochemical characterization. This result indicates the simply prepared hybrid composite was confirmed the formation of Co3O4 has a spherical shape with an anchored surface of GO nanosheets. The proposed sensor has good electron transfer properties and excellent cycling stability. The detection potential difference between DA and UA is + 0.216 V. The electrooxidation response of modified electrode exhibits a wide linear range of DA and UA concentration from 0.2 → 1221 and 0.04 → 1217.2 µM with low detection limits of 0.0874 µM and 0.0131 µM, respectively. Besides, the fabricated sensor has high selectivity, excellent storage stability, reproducibility, and repeatability. Finally, the practical applicability of the contracted sensor was evaluated individual and simultaneous detection of DA and UA in human urine samples with satisfactory results.