Gold nanoclusters encapsulated into zinc-glutamate metal organic frameworks for efficient detection of H₂O₂

Gold nanoclusters (AuNCs) have large Stokes shifts and long fluorescence life, which make them have high application value in bioanalytical applications. However, the quantum yield (QY) of AuNCs was lower, which hinders their wide application. Herein, a facile, novel and one-pot approach was developed to synthesize AuNCs@zinc-glutamate metal organic frameworks (AuNCs@ZnGlu-MOFs (product)). The product was easily prepared via mixing the glutathione (GSH) protected AuNCs with ZnGlu-MOF precursors. Compared with GSH-AuNCs, the ultrahigh QY (33.18%) of the AuNCs@ZnGlu-MOF is nearly 6 times higher. In addition, the product possesses better water stability and longer luminescence life (9.86 μs) due to the protective and confinement effects of the ZnGlu-MOF. Particularly, the product has a unique spatial structure, which can effectively prevent the interaction between large-size biothiols (such as cysteine and homocysteine) and the product, thus significantly improving the selectivity of it. Based on the excellent optical advantages of this product, it was capable of being applied as a selectable and sensitive fluorescence probe to detect H₂O₂ and H₂O₂-related analytes. This method has also been further employed in the precise H₂O₂-monitoring in serum, which is promising in the application of clinical bioassay.