Supramolecular Two‐Photon Switch for Near‐Infrared (NIR) Cell Imaging

Abstract A light controllable two‐photon near‐infrared (NIR) optical probe is conveniently constructed by multivalent supramolecular co‐assembly of amphiphilic sulfonatocalix[4]arene (SC4A), tricationic triphenylamine (TPA), and diarylethene derivative (DE). The obtained results indicate that the formed SC4A/TPA nanoparticle displays assemble‐confined behaviors and enhances the two‐photon excited NIR emission. Benefiting from the reversible ring‐opened and closed behaviors of the DE under 365 and > 600 nm light irradiation, the dicationic DE in the assembly could act as an energy acceptor after 365 nm light irradiation, then the co‐assembly of SC4A/TPA/DE could achieve a NIR fluorescence ON and OFF switch and is successfully applied in HeLa cell imaging, providing a convenient approach to supramolecular two‐photon switch for cell imaging.