Mn2+-doped NaYF4:Yb,Er upconversion nanoparticles for detection of uric acid based on the Fenton reaction.

A novel fluorescence method for the determination of hydrogen peroxide (H2O2) and uric acid (UA) was developed. The procedure was based on the hydroxyl radicals (·OH), which effectively quenched the fluorescence of the Mn2+-doped NaYF4:Yb,Er upconversion nanoparticles (UCNPs). Based on the property of Mn2+-doped NaYF4:Yb,Er upconversion nanoparticles, the Fenton reaction and enzymatic reaction of uric acid, this method could be used for highly sensitive detection of H2O2 and uric acid. Under optimal conditions, we observed that the fluorescence quenching signal showed good linearity with the H2O2 concentration in the range of 3.00×10-8 M ~ 6.00×10-5 M, and the detection limit of this assay was 1.30×10-8 M. Meanwhile, the linear concentration range for UA was 4.00×10-9 M ~ 1.00×10-5 M, and the lower limit of detection was 1.90×10-9 M. Furthermore, the developed method was successfully used for the determination of UA levels in human serum with satisfactory results.