Rhodamine B immobilized on hollow Au-HMS material for naked-eye detection of Hg2+ in aqueous media.

Abstract A simple, effective method has been demonstrated to immobilize Rhodamine B (RhB) probes on mesoporous silica (Au–HMS). The prepared chemosensor (Au–HMS–Probe) was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV–vis spectrum and Fourier transform infrared spectroscopy (FT-IR). Further application of Au–HMS–Probe in sensing Hg 2+ was confirmed by fluorescence titration experiment. Au–HMS–Probe afforded “turn-on” fluorescence enhancement and displayed high brightness in water, and it also showed excellent selectivity for Hg 2+ over alkali (Na + , K + ), alkaline earth (Mg 2+ , Ca 2+ ) and other heavy metal ions (Ag + , Cd 2+ , Co 2+ , Pb 2+ , Ni 2+ , Cu 2+ , Fe 2+ ). Importantly, Au–HMS–Probe could be regenerated by treatment with tetrapropylammonium hydroxide solution.