A New Schiff Base Chemodosimeter for Fluorescent Imaging of Ferric Ions in Living Cells

Abstract

A new and efficient chemodosimeter for ferric ions has been developed. The visual and fluorescent behaviors of the compound toward various metal ions were investigated: ferric ions are distinguished from other cations by selective color change and unusual fluorescence enhancement in mixed aqueous solution. Fluorescence microscopy experiments showed that this receptor is effective for detection of Fe(3+) in vitro, developing a good image of the biological organelles. The sensing mechanism is shown to involve a hydrolysis process.

Recent Advances on Iron(III) Selective Fluorescent Probes with Possible Applications in Bioimaging

“…Besides, the probe 73 could be applied to monitor Fe 3+ within the live HeLa cells. With a similar approach, three more Fe 3+ -selective fluorescent probes 74 - 76 have been reported [83,84,85]. The probe 74 shows significant fluorescence enhancement at 440 nm (λ exc = 396 nm) selectively in the presence of Fe 3+ in DMSO/H 2 O ( v / v = 70:30) due to the Fe 3+ -mediated hydrolytic cleavage of the imine linkage [83].…”

“…With a similar approach, three more Fe 3+ -selective fluorescent probes 74 - 76 have been reported [83,84,85]. The probe 74 shows significant fluorescence enhancement at 440 nm (λ exc = 396 nm) selectively in the presence of Fe 3+ in DMSO/H 2 O ( v / v = 70:30) due to the Fe 3+ -mediated hydrolytic cleavage of the imine linkage [83]. Using 74 , the concentration of Fe 3+ can be detected down to 1.37 μM and successfully applied to detect intracellular Fe 3+ ions in live RAW264.7 cells by imaging experiment.…”

Salicylaldimine‐functionalized poly(m‐phenyleneethynylene) as turn‐on chemosensor for ferric ion

“…However, in recent years, fluorescent turn‐on probes for Fe 3+ based on small molecules were emerging as a new sensor design concept. Generally, salicylaldimine Schiff base is incorporated as a receptor into the chromophores . Owing to isomerization of CN and ESIPT from salicylaldimine group, those probes show weak fluorescent signals in the initial state.…”

Small-Molecule Fluorescent Probes for Binding- and Activity-Based Sensing of Redox-Active Biological Metals

“…Yen and co-workers reported a turn-on probe Tz-1 (120) for the detection of ferric ions in RAW264.7 cells. 204 Dye 120 contains an imine linkage between aminopyrene and 2quinolinecarboxyaldehyde, which displays a weak blue emission band. Fe(III) induces the hydrolysis of the Schiff base, leading to a strong fluorescence enhancement in the emission spectrum.…”