An Ethyl-Thioglycolate-Functionalized Fe 3 O 4 @ZnS Magnetic Fluorescent Nanoprobe for the Detection of Ag + and Its Applications in Real Water Solutions.

Ethyl-thioglycolate-modified Fe 3 O 4 @ZnS nanoparticles (Fe 3 O 4 @ZnS-SH) were successfully prepared using a simple chemical precipitation method. The introduction of ethyl thioglycolate better regulated the surface distribution of ZnS, which can act as a recognition group and can cause a considerable quenching of the fluorescence intensity of the magnetic fluorescent nanoprobe, Fe 3 O 4 @ZnS-SH. Benefiting from stable fluorescence emission, the magnetic fluorescent nanoprobe showed a highly selective fluorescent response to Ag+ in the range of 0-400 μM, with a low detection limit of 0.20 μM. The magnetic fluorescent nanoprobe was used to determine the content of Ag + in real samples. A simple and environmentally friendly approach was proposed to simultaneously achieve the enrichment, detection, and separation of Ag + and the magnetic fluorescent nanoprobe from an aqueous solution. These results may lead to a wider range of application prospects of Fe 3 O 4 nanomaterials as base materials for fluorescence detection in the environment.