A simple, rapid, and effective colorimetric assay for the detection of uric acid (UA) has been built, using the MoS2 nanoflakes-catalyzed 3,3',5,5'-tetramethylbenzidine (TMB)-H2O2 system. In the presence of oxygen and uricase, uric acid was oxidized specifically to produce H2O2. MoS2 nanoflakes synthesized by hydrothermal reaction could catalyze the oxidation of TMB by H2O2, and engendering the colorimetric signal. Finally, the change in the color from colorless to blue was seen with naked eye, indicating the presence or absence of UA. Under the optimized conditions, a linear relationship between the absorbance and UA concentration in the range of 0.5-100 μM (R2 = 0.996) with the limit of detection for 0.3 μM (S/N = 3). The proposed assay was successfully applied to the detection of UA in human serum with the recoveries over 94.54%. Thus, these results suggest that the UA assay-based MoS2-catalyzed TMB-H2O2 has great foreground for fast clinical diagnosis of gout without the need for advanced and costly equipment. Graphical Abstract ᅟ.
Keywords: MoS2 nanoflakes; Serum samples; TMB; Uric acid; Uricase.