Photo-Responsive Fluorescent Materials with Aggregation-Induced Emission Characteristics

Stimuli-responsive fluorescent materials with aggregation-induced emission (AIE) characteristics have attracted increasing attention owing to their advantages of bright fluorescence in the solid state and the ability to tune the structures and physicochemical performances in response to various stimuli. Among all the available external stimuli, light stands out, and has rapidly become a focus of research, because it offers green and remote triggering, noninvasive manipulation, high spatiotemporal resolution, and convenient tunable properties. Consequently, photo-responsive AIE materials provide a fascinating strategy for constructing functional fluorescent materials. This review summarizes the recent advances in the fabrication of photo-responsive fluorescent materials with AIE characteristics by grafting AIE fluorogens (AIEgens) into photochromic molecules. State-of-the-art photo-responsive AIE materials based on the inherent photochemical reactions of AIEgens are highlighted, and are classified and discussed according to the photochemical pathways, including photocyclization, photo-isomerization, photodimerization, photo-removal, and multiple photoreactions. Following this, the corresponding applications of photo-responsive AIE materials in bio-imaging, anti-counterfeiting, photo-patterning, photo-release of chemicals or drugs, and photo-controlled assembly and disassembly are introduced. Finally, the most promising directions for development and applications of photo-responsive AIE materials are outlined and discussed.