A bis-(rhodamine)-based off–on colorimetric and fluorescent probe for Fe3+ ion detection in serum and bioimaging
An off–on colorimetric and fluorescent probe N1, N4-bis (2-(3′, 6′-bis(diethylamino)-3-oxospiro[isoindoline-1,9′-xanthen]-2-yl) ethyl) terephthalamide (Rp) for Fe3+ was designed and synthesized, which could selectively and sensitively respond to Fe3+ among other tested metal cations in THF–H2O solution (v/v = 4/6, pH = 7.2) accompanied with a remarkable fluorescence enhancement and an obvious color change visible to “naked-eye”. The fluorescence intensity of the probe Rp showed a good linearity with the concentration of Fe3+ covering from 0.1 to 26 μM and the detection limit was 0.0231 μM. Meanwhile, the binding mode between Rp and Fe3+ was found to be a 1:2 stoichiometric formation. Moreover, the complexation of Rp–Fe3+ could be broken by carbonate, so this system might be utilized as a carbonate probe in the future. Most importantly, the probe Rp was not only applied to monitor Fe3+ level in human blood serum and water samples, but also was used for fluorescence imaging of Fe3+ in living cell.
KeywordsFluorescent probe Fe3+ Rhodamine Serum Cell imaging
This work was supported by the National Natural Science Foundation of China (11175080), the Natural Science Foundation of Hunan Province, China (2016JJ5003), the Scientific Research Fund of the Hunan Provincial Education Department (12A117).