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

Au–HMS–Probe with worm-like mesoporous framework for detection of Hg2+ in aqueous media has been simply and effectively synthesized by immobilizing a Rhodamine B derivative on Au–HMS via AuN groups under room temperature. [Display omitted] ► Au–HMS–Probe is prepared via AuN bonds. ► Gold nanoparticles are chosen as connectors instead of silane agents. ► Au–HMS is chosen as carrier for the first time. ► The immobilization method of Au–HMS–Probe is very simple and effective. ► Au–HMS–Probe shows excellent ability for detecting Hg2+ by naked-eye. 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 Hg2+ 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 Hg2+ over alkali (Na+, K+), alkaline earth (Mg2+, Ca2+) and other heavy metal ions (Ag+, Cd2+, Co2+, Pb2+, Ni2+, Cu2+, Fe2+). Importantly, Au–HMS–Probe could be regenerated by treatment with tetrapropylammonium hydroxide solution.