Innovative fluorescence sensing platform for β-lactams based on acidity/basicity-sensitive graphdiyne quantum dots.

Residues of β-lactam antibiotics (β-LA) in the environment have posed a great threat to human health, while lacking a simple, effective, and universal sensing method. Herein, basic fuchsin and graphdiyne (GDY) were used as precursors to prepare the first reported acidity/basicity-sensitive GDY quantum dots (S-GDY QDs). We propose a novel fluorescence-sensing strategy for β-LA detection based on the ability of β-lactamases to catalyze β-LA to form carboxylic acid, which further induces a change in the acidity/basicity of the solution and causes a decrease in the fluorescence intensity of S-GDY QDs.

High Peroxidase-Mimicking Metal-Organic Frameworks Decorated with Platinum Nanozymes for the Colorimetric Detection of Acetylcholine Chloride and Organophosphorus Pesticides via Enzyme Cascade Reaction.

The sensitive detection of acetylcholinesterase (AChE) and organophosphorus pesticides (OPs) is very important for the protection of human health. Herein, a hybrid material, Pt NPs/Fe-MOF, consisting of a metal-organic framework (MIL-88B-NH, Fe-MOF) decorated with platinum nanoparticles (Pt NPs), was prepared first and exhibited remarkably improved and excellent peroxidase-mimicking activity compared to the Fe-MOF material resulting from the synergistic catalysis effect between Fe-MOF and Pt NPs, which can effectively catalyze 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to generate a blue product (oxidized TMB, oxTMB). Interestingly, in the presence of AChE and acetylcholinesterase, the peroxidase-mimicking activity from Pt NPs/Fe-MOF was inhibited obviously, and thus, a colorimetric sensing platform for AChE can be constructed; more importantly, after the addition of OPs, this nanozyme activity can be recovered, inducing the further successful construction of a sensitive colorimetric sensing platform for OPs.