A novel DRET and FRET combined fluorescent molecule and its applications in sensing and bioimaging

摘要

The work presented herein is focused on the construction of a donor-acceptor system with large Stokes shift, which could be used for the detection of Fe~(3+) in different polarity environments by combining dark resonance energy transfer (DRET) and fluorescence resonance energy transfer (FRET) strategies. A silole derivative and a rhodamine 6 G derivative, linked by a flexible diethylenetriamine spacer, are chosen as donor and acceptor, respectively. Attributed to its AIE features, silole fluorophore could act both as dark energy donor in solution state and emissive energy donor in aggregation state, and the molecule possesses polarity-sensitive DRET and FRET processes from silole to rhodamine after bonding with Fe~(3+) ion. Thus, intense fluorescence emission from the rhodamine acceptor is obtained no matter whether the test is carried out in solution with high organic solvent content or high water content. Imaging experiments suggest that this probe could be an effective Fe~(3+) imaging agent for use in live cells.