Pyridine salts and aliphatic chains regulating membrane-targeted ratiometric fluorescence probe for detection of SO2 in living cells

Cell membrane is the barrier between cell and environment, which is an important structural basis for main-taining cell environment stability and regulating cell normal life activities. There are important active molecules in the cell membrane, so it is of great biological and medical significance to explore the physiological functions of active molecules in the cell membrane. In this work, probe that co-regulating cell membrane targeting by pyr-idine salts and lipid chains was developed. In this probe, using pyridine salt as receptor and coumarin derivatives as donor constructed a ratiometric fluorescent probe MCP based on ICT for specific recognition of SO2 de-rivatives. MCP was selected the cyanide group as the SO32-response site, and the introduction of pyridine propyl, which regulates hydrophobicity, so as to achieve efficient targeting of cell membranes. MCP showed high sensitivity and selectivity for SO32-. Moreover, MCP showed a fast response time (30 s) and red fluorescence emission wavelength (645 nm). In addition, MCP can successfully applying to detect endogenous SO2 on the cell membranes.