Glassy carbon electrode modified with G‑MoS2‑Nafion acts as an electrochemical biosensor to determine uric acid in human serum.

Abstract

At present, the majority of methods used for uric acid (UA) detection are not able to meet the detection requirements with speed, accuracy, high sensitivity, high specificity, a wide linear range or a low cost. Compared with other methods, the electrochemical method has a high sensitivity and fast detection. The present study aimed to identify an electrochemical sensor with high sensitivity, fast detection and a wide linear range for the detection of UA. A glassy carbon electrode modified with graphene-molybdenum disulfide-Nafion (G-MoS2-Nafion) composites was prepared for use as the working electrode. The morphologies and elemental compositions of the G-MoS2 composites were characterized by field emission scanning electron microscopy, elemental distribution spectrometry and X-ray diffraction, respectively. The electrochemical behaviors were investigated by cyclic voltammetry, linear sweep voltammetry and the amperometric i-t curve (i-t). The interference of glucose, ascorbic acid and dopamine, and the accuracy and precision of the electrochemical method were subsequently evaluated. The present study identified the following: (1) Only the reduction peak of UA was detected in human serum, indicating that the method established in the present study has a high specificity for the determination of UA in human serum; (2) UA concentration has a linear correlation with current intensity (y=0.012×+0.998; R2=0.998), wide linear range and high sensitivity (minimum detectability=13.91 µM; signal-to-noise ratio=3); (3) the values of UA content in human serum were positively proportional to the clinical results (y=0.9802×+11.494; R2=0.978); (4) the average recovery rate of UA (95.28%) and the replicability assay of the i-t electrochemical method (coefficient of variation=2.04%), suggest that the method had a high accuracy and good precision for UA detection. Due to its characteristics of good accuracy, high sensitivity, wide linear range, good anti-interference ability and replicability, G-MoS2-Nafion has good prospects for UA detection in the clinical setting.