Dual-ratiometric fluorescence probe for viscosity and hypochlorite based on AIEgen with mitochondria-targeting ability

Viscous microenvironments are ubiquitous in living organisms. An oxidative stress attack could cause the fluctuation of lymph or blood viscosity, which is closely related to many common diseases. However, the dual-function detection of reactive oxygen species and viscosity is still ineffective due to design defects. Herein, by rational linking a propeller-shaped triphenylamine rotator and a rigid planar anthracene, we report the first dual-ratiometric-response probe for ClO− and viscosity detection. The probe itself shows weak fluorescence background in low-viscous solution or at non-aggregate state, which can largely switch on its blue (414 nm) and yellow fluorescence (600 nm) respectively in response to ClO− and viscosity. Their sensing mechanisms were elucidated through the interruption of FRET and TICT processes for ClO− and viscosity detection, respectively. In addition to its mitochondria targeting ability, TPP-AN was employed for mitochondrial viscosity and ClO− imaging in HeLa cells, providing a potentially useful probe for clinical assays. [Display omitted] •A rigid-fluorophore-molecular rotor TPP-AN is designed with the TICT-FRET effect.•TPP-AN is the first dual-ratiometric-response probe for ClO− and viscosity detection.•A 186 nm gap between two emissions provides a basis for the accurate ratiometric quantifications.•The ratiometric fluorescent assays were successfully confirmed in the mitochondria of living cells.