Spatiotemporal Visualization of Cell Membrane with Amphiphilic Aggregation-Induced Emission Active Sensor

High-fidelity spatiotemporal monitoring of the cell membrane is critically important. However, commercial fluorescence probes are stalked by the aggregation-caused quenching (ACQ) effect, and the reported aggregation-induced emission (AIE)-active probes are always limited by nonspecific aggregations in the biological environment. Herein, we report the rational molecular design of a state-of-the-art amphiphilic AIE luminogen (AIEgen), membrane tracker QMC12, using a core quinoline-malononitrile (QM) structure to suppress the ACQ effect, incorporate a positively charged pyridinium to regulate dispersity and strengthen the binding affinity to the negatively charged cell membrane, and extend the alky chain to improve the anchoring ability to the cell membrane. The membrane tracker QMC12, which disperses well in both hydrophilic and lipophilic environments, not only achieves minimal background interference and high signal-to-noise (S/N) ratio in the "ultrafast" visualization of the cell membrane, but also endows a "wash-free" characteristic. Furthermore, it realizes a spatial three dimensional (3D) view in a multicellular spheroid model and morphology changes over time. Moreover, QMC12 avoids false staining and signal loss and unprecedentedly achieves the direct observation of the cell membrane's microstructure, which could elucidate spatiotemporal 3D model studies of the intercellular information exchange. [GRAPHICS] .