A novel AIEgen fluorescent probe based on quinoline-malononitrile for monitoring and imaging ClO- and viscosity in biosystem.

Hypochlorite (ClO-) and viscosity play a pivotal role in biological immune defense systems, it has been demonstrated that alterations in ClO- may link to the modifications in intracellular viscosity. Consequently, it is crucial to develop a tool that can accurately assess these changes of ClO- and viscosity concurrently. In this work, a dual-responsive fluorescent probe QM-WV based on the ICT effect for simultaneous detection of ClO- and viscosity was constructed. QM-WV exhibited a signally turn-on fluorescence signal at 552 nm for ClO- with favorable selectivity. Meanwhile, QM-WV displayed an exceptional 'off-on' fluorescence response at 650 nm to viscosity changes in glycerol-ethanol system. More importantly, QM-WV is capable of visually detecting ClO- by using smartphone as a portable signal processing device. Based on its low cytotoxicity and stability under physiological conditions, QM-WV further enabled the detection and imaging of ClO- and viscosity in HeLa cells and zebrafish.