A ratiometric fluorescent probe for detection of uric acid based on the gold nanoclusters-quantum dots nanohybrid

Herein, we developed a simple strategy for the preparation of dual-emission fluorescent nanohybrid constructed of gold nanoclusters (Au NCs) and quantum dots (QDs). The bovine serum albumin-capped Au NCs can be directly used as the stabilizers to prepare CdS QDs. The synthesized bovine serum albumin-capped Au NCs and CdS QDs nanohybrid (BSA-Au NCs/QDs) displayed dual emission bands respectively at 490 nm and 685 nm. An obvious fluorescence quenching around 685 nm was detected with the addition of hydrogen peroxide (H2O2) in the presence of Fe2+ ions, and the fluorescence emission peak at 490 nm was not affected. Uricase can break down uric acid to produce H2O2, and we further used the BSA-Au NCs/QDs as a ratiometric fluorescent probe for determination of uric acid with the linear range from 0.67 to 60 μmol·L-1 and the detection limit of 0.21 μmol·L-1.