Zhou Wenjuan, Cao Yuqing, Sui Dandan, Lu Chao
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, PO Box 79, 100029, Beijing, China.
Angew Chem Int Ed Engl. 2016 Mar 18;55(13):4236-41. doi: 10.1002/anie.201511868. Epub 2016 Feb 25.
The utilization of semiconductor quantum dots (QDs) as optical labels for biosensing and biorecognition has made substantial progress. However, the development of a suitable QD-based luminescent probe that is capable of detecting individual reactive oxygen species (ROS) represents a great challenge, mainly because the fluorescence of QDs is quenched by a wide variety of ROS. To overcome this limitation, a novel QD-based turn-on luminescent probe for the specific detection of (.) OH has been designed, and its application in monitoring the endogenous release of (.) OH species in living cells is demonstrated. Metal citrate complexes on the surfaces of the QDs can act as electron donors, injecting electrons into the LUMO of the QDs, while (.) OH can inject holes into the HOMO of the QDs. Accordingly, electron-hole pairs are produced, which could emit strong luminescence by electron-hole recombination. Importantly, this luminescent probe does not respond to other ROS.
将半导体量子点（QDs）用作生物传感和生物识别的光学标记已取得了重大进展。然而，开发一种能够检测单个活性氧物种（ROS）的合适的基于量子点的发光探针是一项巨大的挑战，主要是因为量子点的荧光会被多种ROS淬灭。为了克服这一限制，设计了一种用于特异性检测羟基自由基（·OH）的新型基于量子点的开启型发光探针，并展示了其在监测活细胞中·OH物种内源性释放方面的应用。量子点表面的金属柠檬酸盐配合物可以作为电子供体，将电子注入量子点的最低未占分子轨道（LUMO），而·OH可以将空穴注入量子点的最高已占分子轨道（HOMO）。因此，产生了电子-空穴对，它们可以通过电子-空穴复合发出强烈的荧光。重要的是，这种发光探针不会对其他ROS产生响应。
