Novel controllable (Ba_0.8Sr_0.2)CO₃@Mesoporous silicate core/shell nanocomposite grafted fluorescent probes for colorimetric, sensing, and selective detection of heavy metals

Abstract

Fluorescent nanosensors are one of the most efficient techniques used for detection of toxic metal ions, based on ligand embedded into mesoporous materials. In this study, four different novel nanosensors NS1, NS2, NS3, and NS4 have been synthesized by incorporating fluorescent probes containing dihydropyridine and dihydropyrimidinone fragments into amino‐functionalized controllable (Ba0.8Sr0.2)CO3@Mesoporous silicate core/shell nanocomposite. The designed nanosensors were characterized by FT‐IR (Fourier‐transform infrared spectroscopy), X‐ray diffraction, transmission electron microscopy (TEM), and nitrogen adsorption–desorption isotherms. Visual naked‐eye observations and emission technique were employed to investigate the recognition and sensing capability of the investigated nanosensors toward various metal ions (Al3+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, and Cu2+). A great quenching in the fluorescence intensity was clearly observed with the majority of studied metal ions for all the nanosensors. The binding constants and limit of detection (LOD) have been calculated. Cu2+ is the strongest binded one with both NS1 and NS2, while Al3+ and Fe3+ are the strongest binded metal ions with NS3 and NS4, respectively. The obtained results confirmed the high ability of the nanosensors to detect heavy metals ions at environmentally relevant concentrations using simple and low‐cost experimental studies with good reversibility and reusability.