Application of Aggregation-Induced Emission (AIE) Systems in Sensing and Bioimaging

Compared with the conventional luminescent molecules, whose fluorescence is quenched once they aggregate, molecules with aggregation-induced emission (AIE) properties exhibit significantly enhanced emission in solid state or aggregates due to their unique molecular structures and stacking modes, showing potential applications in optoelectronic devices, biochemical sensors and bioimaging. Especially, AIE fluorophores recently have drawn much attention as an emerging sensory material. Taking advantage of AIE effects, fluorescence signals can be boosted by AIE dyes in presence of analytes, which offers a promising platform for sensor with intense fluorescence signal. In this review, we highlight the recent advances in the development of AIE fluorescent probes that are classified into various categories, including tetraphenylethenes, siloles, 9,10-distyrylanthracene, cyanostilbene and systems with extended π-conjugations to those even without typical AIE chromophores. The fluorescent behaviors of these probes toward different analyte are discussed. Keywords: Aggregation-induced emission (AIE), bioimaging, biological probes, chemical sensors, fluorescence enhancement, fluorescent silica nanoparticles (FSNPs), restriction of intramolecular rotation (RIR).