Novel Lanthanide Fluorescence Probes And Their Application To Time-Resolved Fluorescence Detection Of Singlet Oxygen

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 doctoral dissertation, two new Eu³⁺ chelate-based fluorescence probes specific for singlet oxygen (¹O₂) were designed, prepared, characterized and used for highly sensitive and selective detection of ¹O₂.A new Eu³⁺ chelate, [4'-(9-anthryl)-2,2':6',2"-terpyridine-6,6"-diyl]bis (methylenenitrilo) tetrakis(acetate)-Eu³⁺ (ATTA-Eu³⁺), was designed and synthesized as a time-resolved fluorescence probe for ¹O₂. ATTA-Eu³⁺ itself is almost non-fluorescent, and can specifically react with ¹O₂ to yield its endoperoxide (EP-ATTA-Eu³⁺) with a 17-fold increase of fluorescence quantum yield. The new probe is highly water soluble having a large stability constant, and highly sensitive and selective for ¹O₂ with a wide pH available range and large reaction rate constant.Using ATTA-Eu³⁺, 9,10-diphenylanthracene and 2,2,6,6-tetramethyl-4- piperidinol as the specific probes of ¹O₂, a new system of ¹O₂ generation, the aerobic oxidation system of ascorbate catalyzed by copper ion, was found. The influence factors and mechanism of this system were investigated. By using 10-methyl-9-anthryl group instead of 9-anthryl group in ATTA, an improved Eu³⁺ chelate fluorescence probe specific for ¹O₂, [4'-(10-methyl-9-...