An Ethyl-Thioglycolate-Functionalized FeO@ZnS Magnetic Fluorescent Nanoprobe for the Detection of Ag and Its Applications in Real Water Solutions.

Ethyl-thioglycolate-modified FeO@ZnS nanoparticles (FeO@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, FeO@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 FeO nanomaterials as base materials for fluorescence detection in the environment.