Rhodamine B-based ordered mesoporous organosilicas for the selective detection and adsorption of Al(iii)

Abstract

A novel “Off–On” solid chemosensor based on ordered mesoporous organosilica material was constructed through the co-condensation of rhodamine B organosilanes (RBSi) and tetraethoxysilane (TEOS). The resulting rhodamine B-based hybrid mesoporous organosilicas (RBMSiO₂) show good recognition ability for Al³⁺ on the basis of the “Off–On” mechanism modulated by the Al³⁺-promoted ring-opening process of the spirolactam structure in the rhodamine B diethylenetriamine (RBD). The photo-stability of RBD could be significantly improved after introducing rhodamine B diethylenetriamine into the framework of RBMSiO₂. Upon addition of Al³⁺, fluorescence emission intensity could increase by 110-fold with the color change from colorless to rose-red, and the detection limit of this hybrid chemosensor towards Al³⁺ can be as low as 1.3 × 10⁻⁷ M. Accordingly, the RBMSiO₂ materials have great potential application in environmental and biological fields for the detection of Al³⁺.