Cucurbit[7]uril confined phenothiazine bridged bis(bromophenyl pyridine) activated NIR luminescence for lysosome imaging

Macrocycle confinement induced guest near-infrared (NIR) luminescence was research hotspot currently. Here in, we reported a cucurbit[7]uril (CB[7]) confined 3,7-bis((E)-2-(pyridin-4-yl)vinyl)-10-H-phenothiazine bridged bis(4-(4-bromophenyl)pyridine) (G), which not only boosted its NIR luminescence but also realized detection of HClO/ClO− in living cells and lysosome imaging. Fluorescence spectroscopy experiments were performed to calculate the detection ability of probe G to HClO/ClO− up to 147 nmol/L. As compared with G, supramolecular probe G⊂CB[7] formed after encapsulated by CB[7], the detection ability towards HClO/ClO− was improved to 24 nmol/L which was ascribe to the macrocycle CB[7] confinement increasing the fluorescence intensity to 103 folds. Accompanying the excitation wavelength changing, the fluorescence red-shifted to 820 nm when excited by 570 nm light, which was used to NIR lysosome imaging. Meanwhile, the supramolecular assembly G⊂CB[7] was also successfully used to highly sense to exogenous HClO/ClO− in RAW 264.7 cells and live animal.