Synthesis And Application Of A New Luminescent β-Diketonate-Europium(Ⅲ) Complex

Time-resolved fluorescence bioassay technique, which is an ultrasenstive bioanalytical method, has been widely used in clinical diagnostics and biotechnology. In the study, a new luminescentβ-diketonate-europium complex was designed, synthesized and characterized, and its application for biolabeling was investigated.A new luminescent Eu(III) complex that can be used for biolabeling, 1,2-bis(1",1",1",2",2",3",3"-heptafluoro-4",6"hexanedion-6"-yl-p-benzyl)-4-chlorosulfo-benzene-Eu3+(BHHBCB-Eu3+), has been designed and synthesized. The effects of different surfactants on the luminescence intensity of BHHBCB-Eu3+ were investigated, and the results indicated that the luminescence intensity of BHHBCB-Eu+ was strongest with a large quantum yield of 72% and a long luminescence lifetime of 0.47 ms in 50μmol/L CTAB-containing aqueous buffer of pH 7.4. Because the complex has a chlorosulfonyl group, the complex can be easily covalently conjugated to the amino-containing biological molecules for labeling these molecules. Using bovine serum albumin (BSA) as a model bio-molecule, the performance of BHHBCB-Eu3+ for biolabeling was investigated, and the BHHBCB-Eu3+-labeled BSA was prepared. The luminescence detection results indicate that the BHHBCB-Eu3+-labeled BSA still remains the luminescence properties of BHHBCB-Eu3+ with a larger quantum yield (37%) and a long luminescence lifetime (0.43 ms), which indicates that the new complex BHHBCB-Eu3+ can be used a biolabeling probe for various time-resolved luminescence bioassays.