Electrochemical detection of uric acid in human serum based on ultrasmall Ta 2 O 5 nanoparticle anchored Pt atom with ultrahigh uricase and catalase activities

The synthesis of ultrasmall Ta 2 O 5 nanoparticle anchored Pt atom using aspartic acid-functionalized graphene quantum dot (Asp-GQD) is reported. The Asp-GQD was combined with tantalic acid and chloroplatinic acid to rapidly form water-soluble Ta-Asp-GQD and Pt-Asp-GQD complex. Followed by thermal annealing at 900 °C in N 2 to obtain Ta 2 O 5 -Asp-GQD-Pt. The study shows that the introduction of Asp-GQD as a chelating agent and p-type semiconductor achieves to the formation of ultrasmall Ta 2 O 5 nanoparticle, PN junction at the interface and Pt single atom anchored on the surface of Ta 2 O 5 nanocrystals. The unique structure realizes ultrahigh uricase activity and catalase activities of Ta 2 O 5 -Asp-GQD-Pt. The Ta 2 O 5 -Asp-GQD-Pt was used as the bifunctional sensing material for the construction of an electrochemical uric acid sensor. The differential pulse voltammetric current at 0.45 V linearly increases with the increase of uric acid concentration in the range 0.001–5.00 mM with the detection limit of 0.41 μM ( S/N = 3). The sensor exhibits a much better sensitivity compared with the reported methods for the detection of uric acid. The proposed analytical method has been applied to the electrochemical detection of uric acid in human serum with a spiked recovery of 95–105%. The study also offers one way to design and synthesize multifunctional sensing materials with high catalytic activity. Graphical Abstract