Dye-functional mesoporous silica material for fluorimetric detection of Cr(III) in aqueous solution and biological imaging in living systems

A dye-functionalized silica nanomaterial, SBA-RT was prepared by the immobilization of the Rhodamine-based chemosensor R6G-TETA within the channels of SBA-15. SBA-RT exhibits several different properties compared to the free R6G-TETA, such as higher selectivity, blue-shift of the UV–vis spectra due to special spatial environment in the channels of the mesoporous material. It presents Cr(III)-selective fluorimetric and colorimetric responses in aqueous solution. The fluorescence responses are reversible by treating with EDTA and do not vary over a broad pH range suitable for Cr(III) bioimaging application. Through isolating of the metal ions within the mesopores of the silica, SBA-RT can extract Cr(III) from the solution with only trace amounts remaining. The fluorescence images experiment demonstrated the possibility of further application in monitoring Cr(III) in living cells and organisms.