Semiconducting Polymer Nanoparticles with Persistent Near‐Infrared Luminescence for In Vivo Optical Imaging

Abstract Materials with persistent luminescence are attractive for in vivo optical imaging since they have a long lifetime that allows the separation of excitation of fluorophores and image acquisition for time‐delay imaging, thus eliminating tissue autofluorescence associated with fluorescence imaging. Persistently luminescent nanoparticles have previously been fabricated from toxic rare‐earth metals. This work reports that nanoparticles made of the conjugated polymer MEH‐PPV can generate luminescence persisting for an hour upon single excitation. A near‐infrared dye was encapsulated in the conjugated polymer nanoparticle to successfully generate persistent near‐infrared luminescence through resonance energy transfer. This new persistent luminescence nanoparticles have been demonstrated for optical imaging applications in living mice.