Application of NaYF4:Yb,Er Nanoparticles as Peroxidase Mimetics in Uric Acid Detection

The poly(acrylic acid) functionalized NaYF 4 :Yb,Er nanoparticles (NPs) were found to possess intrinsic peroxidase-like activity, which could catalyze oxidization of 3,3′,5,5′-tetramethylbiphenyl (TMB) by H 2 O 2 to produce a color variation. Using TMB as substrate, we systematically studied the effect of a series of conditions, such as temperature and pH, on the catalytic activity of NaYF 4 :Yb,Er NPs. When combined with uricase, the proposed colorimetric method could be successfully used for the determination of uric acid. Under the optimum conditions, the linear range of this method was from 1.0 × 10 −5 M to 2.0 × 10 −4 M with the detection limit down to 5.3 × 10 −6 M. Moreover, the developed method was applied to detect uric acid in serum samples and the results were in good agreement with those reported by the hospital.