Synthesis Of Novel Terbium Complexes And Application In Time-Resolved Fluorescence Imaging

Time-resolved fluorescence bioassay technique based on long-lived fluorescence of lanthanide probes is an ultrasenstive bioanalytical method, and has been widely used in clinical diagnostics and biotechnology. In this work, two kinds of Tb3+fluorescent complexes were designed, prepared, characterized, and developed for time-resolved fluorescence imaging detection as fluorescence probes.A five-carboxyl group containing Tb3+complex, N,N,N1,N1-[2,6-bis(3'-aminomethyl-1' pyrazolyl)-4-carboxyl pyridine] tetrakis (acetate-acid)-Tb3+(BCTA-Tb3+), has been designed and synthesized. The BCTA-Tb3+is strongly fluorescent with quantum yield of 0.088 and long lifetime of 2.67 ms. The detection limit for the BCTA-Tb3+in aqueous solution is 3.64 x 10-13 mol/L.The remarkably high sensitivity incidates that the new terbium complex has potential use in the high-sensitivity time-resolved fluorescence and biochemical analysis.A aldehyde group containing Tb3+ complex, N,N,N1,N1-[2,6-bis(3'-aminomethyl-l'-pyrazolyl)-4-carboxaldehyde pyridine] tetrakis (acetate-acid)-Tb3+(BCPTA-Tb3+), has been designed and synthesized, and was characterized by using the NMR and elemental analysis. The BCPTA-Tb3+is strongly fluorescent with quantum yield of 0.073 and lifetime of 2.74ms. In addition, the aldehyde of the BCPTA-Tb3+facilitates the labeling process of the complex with proteins or oyher amino compounds.After conjugated with streptavidin (SA), the conjugations SA-BCTA-Tb3+and SA-BCPTA-Tb3+ were used for the time-gated luminescence imaging detection of environmental pathogen Giardia lamblia and Cryptosporidium parvum, respectively. The results demonstrated the efficacy of the two novel Tb3+-probes for high sensitivity time-resolved luminescence bioassays.