Colorimetric detection of uric acid in human urine and serum based on peroxidase mimetic activity of MIL-53(Fe)

The porous metal-organic framework MIL-53(Fe) was prepared using a simple solvothermal method, using FeCl3 center dot 6H(2)O and 1,4-benzenedicarboxylic acid as the precursor, and characterized by X-ray diffractometry, Fourier transform infrared spectroscopy and scanning electron microscopy. The MIL-53(Fe) was demonstrated to possess an intrinsic peroxidase-like activity, and it could catalyze the oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine into a blue colored product in the presence of H2O2. Based on this phenomenon, MIL-53(Fe) was developed as a colorimetric sensor for the detection of uric acid (UA) in human urine and serum. This provided a simple and effective method for UA detection using uricase and MIL-53(Fe), with a linear range from 4.5 to 60 mu M, and a detection limit of 1.3 mu M (S/N = 3). Moreover, the proposed method can be successfully applied to the determination of UA in human urine and serum samples with recoveries and relative standard deviations between 1.2-4.8% and 89.50-101.44%, respectively.