Rational construction of AIEgens with wide color tunability and their specific lipid droplet imaging applications.

Organic light-emitting materials with aggregation-induced emission (AIE) character have experienced a rapid development in imaging, visualization and sensing. In this paper, by installing rotors to an aggregation-caused quenching (ACQ) compound, we constructed an AIE luminogen (AIEgens) system (A2-A4, B1-B3) with wide emission tunability, which covers almost all regions of visible light (400-780 nm). The calculated energy gap of the compounds is consistent with the value of the absorption transition. In the biological experiments, B3 showed excellent lipid droplet (LD) targeting ability in PC12 cells, and higher photostability compared with the commercial LDs bioprobe. Moreover, as a hydrophobic compound, B3 can distinguish blood from a hyperlipidemia patient and normal people. Thus, this study provides a strategy to construct red/NIR fluorescent materials with AIE character, and further apply it to identify the blood of people with hyperlipidemia.