A FRET probe with AIEgen as the energy quencher: dual signal turn-on for self-validated caspase detection. Issue 7 (23rd March 2016) - Yuan, Youyong
Abstract : A new generation of FRET probe, based on coumarin (Cou) as the energy donor and AIEgen (TPETP) as the energy quencher conjugated via an Asp-Glu-Val-Asp (DEVD) substrate was developed for self-validated caspase-3 detection with dual fluorescent signal turn-on. Abstract : The accurate detection of biological substances is highly desirable to study various biological processes and evaluate disease progression. Herein, we report a self-validated fluorescent probe which is composed of a coumarin fluorophore as the energy donor and a fluorogen with aggregation-induced emission characteristics (AIEgen) as the energy quencher linked through a caspase-3 specific peptide substrate. Unlike the traditionally widely studied fluorescence resonance energy transfer (FRET) probes, our new generation of FRET probe is non-fluorescent itself due to the energy transfer as well as the dissipation of the acceptor energy through the free molecular motion of AIEgen. Upon interaction with caspase-3, the probe displays strong green and red fluorescent signals synchronously due to the separation of the donor–quencher and aggregation of the released AIEgen. The fluorescence turn-on with dual signal amplification allows real-time and self-validated enzyme detection with a high signal-to-background ratio, providing a good opportunity to accurately monitor various biological processes in a real-time manner.