A novel diethyl 2-(9-fluorenyl) malonate functionlized SBA-15 for selective optical sensing of Iron

In this study, highly ordered mesoporous silica material (SBA-15) functionalized with Diethyl 2 - (9 -fluorenyl) malonate as a flourophore is reported. The anchoring of flourophores to the hydroxyl group on SBA-15 surface was done with post synthesis method. The obtained materials were characterized by small and wide angle X-ray diffraction, N2 adsorption–desorption, Fourier transform infrared spectroscopy and thermogravimetric analysis that indicate the successful immobilization of Diethyl 2 - (9 -fluorenyl) malonate on the surface of mesoporous silica. This organic–inorganic hybrid displayed highly selective and sensitive to Fe3+ ion over other cations such as Mg2+, Cr3+, Co2+, Ni2+, Cu2+, Hg2+ and Zn2+. Turn-off photoluminescence of this material was remarkably observed for iron ions in comparing of the other cations. A good linearity between the fluorescence intensity of the prepared material and the concentration of Fe3+ ion is constructed, which enables this martial as a fluorescence chemo sensor for detecting the Fe3+ ion with a suitable detection limit.