Target-triggering, signal-amplified chemo/bio-sensors based on aggregation-induced emission luminogens

By virtue of their unique luminescent properties, high quantum efficiency, large Stokes' shift, and photostability, aggregation-induced emission luminogen (AIEgens)-based materials have attracted a great deal of attention, especially for detection and bioimaging applications. Upon interaction with targets, the signal intensity (e.g., fluorescence) of AIEgen-based probes changes, allowing for recognition and detection both with high sensitivity and specificity. In this review, we summarize the AIEgen-based probes with target-triggering signal amplification abilities. These species could realize enhanced sensing in terms of both accuracy and detection rate. The probes are classified into three groups according to the different methods of signal output amplification: cross-linking reaction-based, elongation reaction-based, and enzyme-assisted isothermal amplified. In each strategy, the representative design concepts and specific detection applications are presented. Finally, the current limitations of AIEgen-based probes and some promising future directions for the field are also discussed.