Highly selective recognition of Al3+ and I- ions using a bi-functional fluorescent probe.

A tripodal fluorescent probe L1 armed with Rhodamine B and 1-naphthaleneisothiocyanates was prepared in high yield. A study of the recognition properties revealed that probe L1 exhibited high sensitivity and selectivity towards Al3+ through a "FRET" fluorescence response and colorimetric response with low detection limits of the order of 10-8 M. Meanwhile, probe L1 also possessed high recognition ability for I- through fluorescence decay, which given there are comparatively few selective fluorescent probes for I-, is significant. Furthermore, the complexation mechanisms were fully investigated by spectral titrations, 1H NMR spectroscopic titrations and mass spectrometry. The utility of probe L1 as a biosensor in living cells (PC3 cells) towards Al3+ ions has also been demonstrated.