Photo‐Responsive Fluorescent Materials with Aggregation‐Induced Emission Characteristics

Abstract

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.

Functional Polymer Systems with Aggregation-Induced Emission and Stimuli Responses

“…By changing the irradiation time and light intensity as well as the wavelength range of the light source, the strength of the response can be finely tuned. The most studied photo-responsive molecules include azobenzene, spiropyran, spirooxazine, fulgide, and dithienylethene (DTE) derivatives [70]. Functional photo-responsive polymers are generally constructed by chemically incorporating these photo-responsive units into polymer structures or physically blending the photo-responsive molecules in polymer matrices.…”

Photo-Switchable Aggregation-Induced Emission of Bisthienylethene-Dipyrimido[2,1-b][1,3]benzothiazole Triad

“…Molecules 2021, 26, x FOR PEER REVIEW 2 of 8 cyanostilbene [14,15], tetraphenylethene [16][17][18], and bispyridine salt [19], have been obtained as photo-switchable AIE materials [20,21].…”

“…However, their photo-controlled modulation of solid-state fluorescence was not well realized. Currently, only a limited number of dyads and triads, which directly connect a bisthienylethene (BTE) with one or two AIEgens, such as transcyanostilbene [14,15], tetraphenylethene [16][17][18], and bispyridine salt [19], have been obtained as photo-switchable AIE materials [20,21].…”

Materials with aggregation-induced emission characteristics for applications in diagnosis, theragnosis, disease mechanism study and personalized medicine

“…The strong solid-state emission of AIEgens makes them excellent candidates for solid-state applications, while the fluorescence responses of AIEgens upon forming aggregates or disaggregation facilitate the construction of variable sensing systems based on AIEgens. As such, lots of attempts have been made to explore their practical applications in sensing, [10][11][12] imaging, 13-21 display [22][23][24][25] and smart materials [26][27][28][29][30] . Intriguingly, some AIEgens demonstrate the ability to sensitize the formation of reactive oxygen species (ROS) upon light irradiation.…”