Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
Biosens Bioelectron. 2014 Aug 15;58:205-8. doi: 10.1016/j.bios.2014.02.060. Epub 2014 Mar 7.
We have developed a new dual-color fluorescent biosensor for protein detection based on terminal protection of small-molecule-linked DNA and the enzymolysis of exonuclease III (Exo III). The determination of streptavidin (SA) was realized via fluorescence signals of the green color from quantum dots (QDs) and the red from Ru(phen)2(dppx). In the absence of SA, biotin-DNA was degradated by the Exo III, thus making the Ru(phen)2(dppx) employed as a fluorescence quencher to the QDs. With the addition of SA, dual-color response appeared because of the specific binding between SA and biotin so that the biotin-dsDNA was protected and combined with Ru(phen)2(dppx), leading to the QDs recovery and the generating of Ru(phen)2(dppx) fluorescence. This sensor exhibited high sensitivity with a low detection limit (2.11ng/mL) and firstly introduced dual-color QDs-ruthenium complex dyads to protein assay.
我们开发了一种新的双色荧光生物传感器，用于基于小分子连接的 DNA 的末端保护和核酸外切酶 III（Exo III）的酶解的蛋白质检测。通过量子点（QDs）的绿色荧光和 Ru(phen)2(dppx)的红色荧光来实现链霉亲和素（SA）的测定。在不存在 SA 的情况下，生物素-DNA 被 Exo III 降解，从而使 Ru(phen)2(dppx)用作 QDs 的荧光猝灭剂。随着 SA 的加入，由于 SA 和生物素之间的特异性结合，出现了双色响应，从而保护了生物素-dsDNA 并与 Ru(phen)2(dppx)结合，导致 QDs 恢复并产生 Ru(phen)2(dppx)荧光。该传感器具有高灵敏度和低检测限（2.11ng/mL），并首次将双色 QDs-钌配合物二聚体引入蛋白质测定中。
