Organic–inorganic nanohybrids and their applications in silver extraction, chromogenic Cu2+ detection in biological systems, and hemolytic assay

Abstract

Fluorescent organic nanoparticles (FONPs) were prepared from an organic tripodal Schiff base ligand (OTL) in pure water by implementing the re-precipitation method. The FONPs were perfectly spherical in shape and their size increased with the increase in the amount of OTL. Bigger FONPs were more fluorescent than the smaller ones and their fluorescent emission showed a strong temperature dependence due to their amorphous nature. They demonstrated specific binding towards Ag⁺ ions which resulted in a strong reducing ability from Ag(I) to Ag(0) to produce organic–inorganic hybrid nanoparticles (i.e. Ag@FONPs). FONPs and Ag@FONPs were characterized by UV-visible, fluorescence, transmission electron microscopic (TEM), NMR, IR, and XRD studies. We showed that the FONPs can be repeatedly used for the extraction of Ag in a systematic manner, while Ag@FONPs can be used for the chromogenic detection of Cu²⁺ in biological systems even in the presence of other metal ions. A detailed hemolytic analysis demonstrated that the smaller Ag@FONPs can also be suitable drug release vehicles in systematic circulation in comparison to the bigger ones.