Selective detection of Hg2+ ion in aqueous medium with the use of 3-(pyrimidin-2-ylimino)indolin-2-one-functionalized SBA-15

摘要

An isatin-based fluorophore, 3-(pyrimidin-2-ylimino)indolin-2-one, was grafted on a large-pore mesoporous silica material (SBA-15) via a two-step modification process. The obtained material (SBA-Is-Py) was characterized using various techniques and the characterization showed that the ordered porous structure was preserved after the post-grafting procedure. The optical sensing ability of SBA-Is-Py was studied upon the addition of a variety of metal ions and a marked fluorescence quenching by Hg2+ ion was observed. SBA-Is-Py exhibited excellent Hg2+-specific luminescence quenching over various competing cations. Furthermore, linear changes of the optical properties of SBA-Is-Py as a function of the concentrations of Hg2+ ion were found, with a calculated detection limit of 3.28x10(-7)M. In addition, SBA-Is-Py was successfully employed for the determination of Hg2+ in real water samples.