Fe3+-selective naked-eye ‘off–on’ fluorescent probe: its crystal structure and imaging in living cells

Four novel rhodamine-active probes L1–L4 have been proposed and characterized as fluorescent chemosensors for Fe3+. An ‘off-on’ type fluorescent enhancement was observed, which was induced by the interactions between Fe3+ and the probe, proven to adopt a 1:1 binding stoichiometry. The recognition properties of the target compounds with metal ions have been investigated in methanol–water (1:1, v/v) solution by the fluorescence and ultraviolet spectrum. In addition, a plausible application of probes in the imaging of HepG2 (liver cells) under the condition of reoxygenation (95% air, 5% CO2) exposed to Fe3+ ions was also demonstrated.

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