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根据荧光共振能量转移理论合成出一种新颖的分子灯塔探针.由于CdTe量子点(QD s)的荧光发射光谱与DABCYL的紫外-可见吸收光谱有很好的重叠性,所以此种探针采用CdTe量子点作为能量给体,DABCYL作为能量受体.通过水相法合成出直径为2.5 nm的CdTe量子点,并且在偶联剂1-乙基-3-(3-二甲基氨丙基)碳二亚氨盐酸盐(EDC)作用下,与5-′NH2-DNA-DABCYL连接得到了分子灯塔探针.实验发现探针的荧光强度相比CdTe-DNA有明显的下降,最大能量转移效率为68.3%,表明CdTe QD s和DABCYL之间发生了荧光共振能量转移.结果表明,此种探针体系对于互补DNA及其变种有着很好的特异性,且其检测极限为5.170×10-9mol/L.
According to the theory of fluorescence resonance energy transfer, a novel molecular beacon probe has been synthesized.As the fluorescence emission spectrum of CdTe quantum dots (QDs) has a good overlap with the UV-visible absorption spectrum of DABCYL, CdTe QDs as energy donor and DABCYL as energy acceptor.The CdTe QDs with the diameter of 2.5 nm were synthesized by aqueous phase method and characterized in the presence of 1-ethyl-3- (3-dimethylaminopropyl) ) Was added to the 5 ’’ NH2-DNA-DABCYL under the action of carbodiimide hydrochloride (EDC), and the fluorescence intensity of the probe was significantly lower than that of CdTe-DNA. The maximum energy The transfer efficiency was 68.3%, indicating fluorescence resonance energy transfer between CdTe QDs and DABCYL.The results showed that this probe system has good specificity for the complementary DNA and its variants, and its detection limit is 5.170 × 10 -9mol / L.