Sensitive and Highly Selective Biosensor Based on Triangular Au Nanoplates for Detection of Uric Acid in Human Serum

Abstract

Herein a uric acid (UA) biosensor based on triangular Au nanoplates–uricase was presented. In the presence of uricase and oxygen, UA was oxidized to produce H2O2. H2O2 etched the active “tips” area of the triangular Au nanoplates, eventually, it results in great increase in ultraviolet absorbance strength of triangular Au nanoplates. Under the optimized conditions, a linear relationship between the absorbance of triangular Au nanoplates and UA concentration ranged from 0.0027 to 0.5333 μM (R2 = 0.9959) with the detection limit of UA for 0.0013 μM (S/N = 3). Some of the interfering substances (e.g., histidine, glycine, valine and tryptophan) in human serum have no effect on the experiment. Serum samples could be detected directly with the sensing system and the obtained results are in agreement with the biochemistry analyzer test results with the average relative error for 3.9%. These results suggest that the proposed UA sensor has great potential in applications for clinical diagnosis.