Controlled Assembly of AIE Active Bolaamphiphilic Macromolecules into Luminescent Organic Nanoparticles Optimized for Two-Photon Microscopy in vivo

The (Z) and (E) isomers of an extended tetraphenylethylene-based chromophore with optimized two-photon induced luminescence properties are separated and functionalized with water-solubilizing pendant polymer groups, promoting their self-assembly in physiological media in the form of small, colloidal stable organic nanoparticles. The two resulting fluorescent suspensions are then evaluated as potential two-photon luminescent contrast agents for intravital epifluorescence and two-photon fluorescence microscopy. Comparisons with previously reported works involving similar fluorophores devoid of polymer side chains illustrate the benefits of the later functionalization regarding the control of the self-assembly of the nano-objects, and ultimately their biocompatibility towards the imaged organism.