A water-soluble diaminostilbene derivative as a two-photon fluorescent probe

A hydrophilic trans-4,4\u27-diaminostilbene derivative was prepared by the introduction of amideamino peripheral substituents. Very high aqueous solubility was achieved ( \u3e 15 mM), making it possible as a fluorescent probe for biological imaging. The relatively straightforward synthetic methodology has great potential to transform even large hydrophobic two-photon absorbing chromophores into hydrophilic derivatives. The fluorescence quantum yield of 0.27 for the diammostilbene in water is sufficiently high for use as a fluorescent probe. In addition, two-photon fluorescence images of NT2 cells stained by this probe were also obtained