Core-shell mesoporous silica nanospheres used as Zn2+ ratiometric fluorescent sensor and adsorbent

Core-shell mesoporous silica nanospheres encapsulated with rhodamine 101 into the solid core and 8-aminoquinoline derivatives into the mesoporous shell were used as a ratiometric fluorescent sensor to detect metal ions, which shows a high selectivity and sensitivity to Zn2+. Concentrations as low as 5 x 10(-8) M can be detected and the addition of other metal ions has a negligible influence on the fluorescence emission. Moreover, the dye-doped nanospheres show excellent photostability, no dye leaking and a good adsorption capacity to Zn2+, which make it repeatedly applicable for simultaneous heavy metal ion sensing and removal from polluted water.