Polynuclear Sm~(III) Polyamidoamine-Based Dendrimer: A Single Probe for Combined Visible and Near-Infrared Live-Cell Imaging

摘要

We report herein the synthesis of a luminescent polynuclear dendritic structure (Sm~(III)-G3P-2,3Nap) in which eight Sm~(III) ions are sensitized by thirty-two 2,3-naphthalimide chromophores. Upon a single excitation wavelength, the dendrimer complex exhibits two types of emission in the visible and in the near-infrared (N1R) ranges. Sm~(III)-G3P-2,3Nap was non-cytotoxic after 24 h of incubation and up to 2.5 μM. The ability of the Sm~(III)-based probe to be taken up by cells was confirmed by confocal microscopy. Epifluorescence microscopy validated Sm'"-G3P-2,3Nap as a versatile probe, capable of performing interchangeably in the visible or NIR for live-cell imaging. As both emissions are obtained from a single complex, the cytotoxicity and bio distribution are inherently the same. The possibility for discriminating the sharp Sm~(III) signals from auto fluorescence in two spectral ranges increases the reliability of analysis and reduces the probability of artifacts and instrumental errors.