双光子激发的超分子聚合物纳米颗粒生物成像研究

A difluoroboron β-diketonate derivative(BF₂-bisUPy)and a porphyrin derivative (Por(Pt)-bisUPy)bearing bis-2-ureido-4[1H]-pyrimidinone (bisUPy)were assembled into a supramolecular polymer by quadruple hydrogen bonding, which afforded uniformly water-dispersed supramolecular polymer nanoparticles by microemulsion method. Scanning electron microscopy shows that the obtained nanoparticles have a particle size of about 60 nm. Ultraviolet-visible absorption spectroscopy, fluorescence emission spectroscopy and lifetime decay experiments have demonstrated the occurrence of efficient energy transfer between BF₂-bisUPy and Por(Pt)-bisUPy. BF₂-bisUPy has excellent two-photon absorption performance, which can be used as an energy donor to enhance the luminescence properties of Por(Pt)-bisUPy under two-photon excitation by fluorescence resonance energy transfer(FRET). The prepared supramolecular polymer nanoparticles have strong fluorescence and phosphorescence dual-emission under two-photon excitation. The nanomaterials can enter cells and exhibit excellent biocompatibility. It also exhibits bright bioimaging with dual-emission under two-photon excitation.