水溶性可见光激发铕荧光生物标记物的制备与应用

For most luminescent lanthainde biolabels, one of the major drawbacks is that the optical excitation window is limited to the UV region, which has stronger phototoxicity on the living biological samples. Although the excitation wavelengths for several Eu3+ complexes can be extended into the visible region, water insolubility, poor stability in polar solvents, low luminescence quantum yield, and the lack of active groups of these complexes make them cannot be used for biolabeling. In this work, by conjugating bovine serum albumin (BSA) with a visible-light-sensitized Eu3+ complex, a Eu3+ complex-BSA conjugate , which has good water solubility, visible-light excitability (<460nm), longer luminescence lifetime (0.46ms), and larger quantum yield (27%) was prepared. The Eu3+ complex-BSA conjugate-labeled streptavidin was perpared, and successfully used for immuno-staining and time-resolved luminescence imaging detection of an environmental pathogen, Cryptosporidium parvum, in the water sample.