A Novel Europium Chelate Coated Nanosphere for Time-Resolved Fluorescence Immunoassay

作者：Shen, Yifeng; Xu, Shaohan; He, Donghua^*

来源：PLos One, 2015, 10(6): e0129689.

DOI：10.1371/journal.pone.0129689

• SILICA NANOPARTICLES
• REAGENT

A novel europium ligand 2, 2', 2 '', 2 '''-(4, 7-diphenyl-1, 10-phenanthroline-2, 9-diyl) bis (methylene) bis (azanetriyl) tetra acetic acid (BC-EDTA) was synthesized and characterized. It shows an emission spectrum peak at 610 nm when it is excited at 360 nm, with a large Stock shift (250 nm). It is covalently coated on the surface of a bare silica nanosphere containi free amino groups, using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-Hydroxysuccinimide. We also observed an interesting phenomenon that when BC-EDTA is labeled with a silica nanosphere, the chelate shows different excitation spectrum peaks of about 295 nm. We speculate that the carboxyl has a significant influence on its excitation spectrum. The BC-EDTA/Eu3+ coated nanosphere could be used as a fluorescent probe for time-resolved fluorescence immunoassay. We labeled the antibody with the fluorescent nanosphere to develop a nanosphere based hepatitis B surface antigen as a time-resolved fluorescence immunoassay reagent, which is very easy to operate and eliminates potential contamination of Eu3+ contained in the environment. The analytical and functional sensitivities are 0.0037 mu g/L and 0.08 mu g/L (S/N >= 2.0) respectively. The detection range is 0.08-166.67 mu g/L, which is much wider than that of ELISA (0.2-5 mu g/L). It is comparable to the commercial dissociation-enhanced lanthanide fluoro-immunoassay system (DELFIA) reagents (0.2-145 mu g/L). We propose that it can fulfill clinical applications.

• 出版日期2015-6-9
• 单位福建医科大学