Lipid droplet-targeted AIEgen with dual-responsiveness for sulfur dioxide and viscosity monitoring in live-cell imaging and food analysis

Sulfur dioxide (SO 2 ) and viscosity play pivotal roles in regulating the physiological function within organisms. The abnormal levels of SO 2 and viscosity can lead to various diseases, emphasizing the need for reliable detection methods in biological and real food samples. Herein, we introduce a lipid droplet-targeted novel triphenylamine-based fluorescent probe, TPA-CN , which exhibits aggregation-induced emission (AIE) properties for dual response to SO 2 and viscosity. The TPA-CN could ratiometrically recognize SO 2 with several advantages, such as excellent selectivity and anti-interference, rapid response rate, good sensitivity, and wide pH adaptability. The TPA-CN was also applied to monitor the changes in viscosity through the twisted intramolecular charge transfer (TICT) mechanism. In addition, bioimaging results demonstrated that TPA-CN can effectively monitor endogenous and exogenous SO₂ as well as viscosity in real time, with specific targeting of lipid droplets. Moreover, TPA-CN facilitates determining SO 2 levels in water and food samples, demonstrating robust recovery performance.