New rhodamine B-based chromo-fluorogenic probes for highly selective detection of aluminium(iii) ions and their application in living cell imaging.

Two rhodamine B-based fluorescent probes, BOS1 and BOS2, were designed and synthesized with good yields the condensation reactions between the -diaminobenzene modified rhodamine core structure (RBO) and salicylaldehyde derivatives. Both the probes exhibited remarkable absorbance-on and fluorescence-on responses to Al over other metal ions in ethanol-water (1 : 9, v/v) medium the rhodamine ring-opening approach, which can be used for "naked-eye" Al detection over a broad pH range (5-9). The fluorescence intensities of the probes were linear with the Al ion concentration, resulting in a low limit of detection of 1.839 μM (BOS1) and 1.374 μM (BOS2) for Al. In addition, the MTT assays and cell imaging experiments of Al in SGC-7901 living cells demonstrated that the probes had negligible cytotoxicity, and were cell permeable and suitable for sensing Al in biological systems.