A unique rhodamine-based ‘off–on’ molecular spy for selective detection of trivalent aluminum and chromium ions: Synthesis, crystal structure and spectroscopic properties along with living cell imaging

• Benzodioxole functionalized rhodamine derivative L was synthesized as selective fluorescent probes for Al3+ and Cr3+.
• Probe L displayed highly selective fluorescence enhancements with Al3+ and Cr3+ via CHEF mechanism.
• Probe L was successfully applied to image Al3+ in the HeLa cell.

The well known rhodamine framework offers an ideal model for the development of fluorescence enhanced chemosensors. Herein, a novel and simple molecule chemosensor, (E)-2-((benzo[d][1,3]dioxol-4-ylmethylene)amino)-3′,6′-bis(diethylamino)spiro[isoindoline-1,9′-xanthen]-3-one (L), has been designed by combining a rhodamine B hydrazide and a benzo[d][1,3]dioxole-4-carbaldehyde in a single molecule to prove the selectivity and sensitivity for Al3+ and Cr3+ in a dual-channel mode (fluorescence emission and UV–Vis). The signal transduction occurred by the increase of conjugation in the ring-open form than in the ring-closed form. Furthermore, the chemosensor L could also be used as an imaging probe without cytotoxicity for uptake and detection of Al3+ ion in HeLa cells.

We have synthesized a novel benzodioxole functionalized rhodamine derivative L, which showed a reversible dual chromo- and fluorogenic response exclusively towards Al3+ and Cr3+ ions despite the presence of other competing metal ions. The signal transduction occurred by the increase of conjugation in the ring-open form than in the ring-closed form. Furthermore, the chemosensor L could also be used as an imaging probe without cytotoxicity for uptake and detection of Al3+ ion in HeLa cells.Figure optionsDownload as PowerPoint slide