Development of a Gold Nanoparticle-catalyzed Off-On Fluorescence Probe for Determination of Uric Acid in Urine Samples

In the current work, a fluorescence off-on system was developed and validated for uric acid analysis in urine, based on fluorescein, H2O2 and gold nanoparticles (Au NPs). First, the fluorescence intensity of fluorescein was greatly quenched (off mode) in interaction with H2O2 in the presence of Au NPs, then fluorescence restoring occurred (on mode) with uric acid adding according to its good reduction activity for interaction with H2O2. The emission-enhancing value was well linearly depend on uric acid concentration in the range of 0.3-8.0 & mu;g.mL(-1) with a detection limit of 0.12 & mu;g.mL(-1). The results of the developed probe for uric acid analysis in real samples were compared to a standard method and their good compatibility showed the high potential of the probe for uric acid analysis in urine samples.

Automated summary

A fluorescence off-on system was developed for uric acid analysis in urine using fluorescein, H2O2, and gold nanoparticles (Au NPs). The system showed quenched fluorescence in the presence of Au NPs and H2O2, but restored fluorescence when uric acid was added due to its interaction with H2O2. The system exhibited linear dependence on uric acid concentration in the range of 0.3-8.0 μg.mL(-1), with a detection limit of 0.12 μg.mL(-1). The results compared to a standard method showed high compatibility and potential for uric acid analysis in urine samples.