Cu2+ fluorescent sensor based on mesoporous silica nanosphere

Monodisperse mesoporous silica nanosphere (MSN) modified with anthracene derivative, 2-(3-(triethoxysilyl) propylamino)-N-(9-anthryl methyl) acetamide (SGAAn) has been fabricated as a fluorescent sensor (SGAAn-MSN) for the detection of metal ions, which shows an exclusive selectivity to Cu2+. Compared with SGAAn, SGAAn-MSN presents a higher sensitivity to Cu2+. The loading amount of SGAAn in MSN has a great influence on the detection sensitivity of SGAAn-MSN, which varies with the local concentration and accessibility of SGAAn in the pore channel of MSN. Interference studies indicate that the addition of other metal ions such as Ag+, Cd2+ and Pb2+ has a negligible effect on the selectivity of SGAAn-MSN to Cu2+. The possible mechanism for the sensing behavior of SGAAn-MSN to Cu2+ is proposed based on the relation between fluorescence quench degree and Cu2+ concentration. [Display omitted] ► Cu2+ fluorescence sensor based on MSN was fabricated. ► The sensor has high detection sensitivity to Cu2+. ► The improved sensitivity is attributed to the high local concentration of dye molecules in MSN. ► The dye molecules loading amount has a great influence on the detection sensitivity.