Han Gang, Mokari Taleb, Ajo-Franklin Caroline, Cohen Bruce E
Biological Nanostructures Facility, The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J Am Chem Soc. 2008 Nov 26;130(47):15811-3. doi: 10.1021/ja804948s.
Photoactivatable organic fluorophores and fluorescent proteins have been widely adopted for cellular imaging and have been critical for increasing temporal and spatial resolution, as well as for the development of superresolution microscopy techniques. At the same time, semiconducting nanocrystal quantum dots (QDs) have shown superior brightness and photostability compared to both organic fluorophores and proteins. As part of our efforts to develop nanoparticles with novel optical properties, we have synthesized caged quantum dots, which are nonluminescent under typical microscopic illumination but can be activated with stronger pulses of UV light. We show that ortho-nitrobenzyl groups efficiently quench QDs of different compositions and emissions and can be released from the nanoparticle surface with UV light, both in solution and in live cells. This caging is dependent on the emission of the QD, but it is effective through the visible spectrum into the nIR, offering a large array of new colors for photoactivatable probes. Like organic and protein-based photoactivatable probes, caged QDs can confer increased spatial and temporal resolution, with the added brightness and photostability of QDs.
光可激活有机荧光团和荧光蛋白已被广泛应用于细胞成像，对于提高时间和空间分辨率以及超分辨率显微镜技术的发展至关重要。与此同时，半导体纳米晶体量子点（QDs）与有机荧光团和蛋白质相比，显示出更高的亮度和光稳定性。作为我们开发具有新型光学性质的纳米颗粒工作的一部分，我们合成了笼形量子点，其在典型的显微镜照明下不发光，但可以用更强的紫外光脉冲激活。我们表明，邻硝基苄基能有效地淬灭不同组成和发射的量子点，并且在溶液和活细胞中都能用紫外光从纳米颗粒表面释放出来。这种笼蔽作用取决于量子点的发射，但在可见光谱到近红外光谱范围内都是有效的，为光可激活探针提供了大量新的颜色。与基于有机和蛋白质的光可激活探针一样，笼形量子点可以提高空间和时间分辨率，并具有量子点额外的亮度和光稳定性。
