Korea Institute of Ceramic Engineering and Technology , 101 Soho-ro, Jinju-si, Gyeongnam 52851, South Korea.
Department of Convergence Medicine, University of Ulsan College of Medicine & Asan Institute for Life Sciences , Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea.
J Am Chem Soc. 2017 Jun 7;139(22):7603-7615. doi: 10.1021/jacs.7b02530. Epub 2017 May 25.
Photoswitching or modulation of quantum dots (QDs) can be promising for many fields that include display, memory, and super-resolution imaging. However, such modulations have mostly relied on photomodulations of conjugated molecules in QD vicinity, which typically require high power of high energy photons at UV. We report a visible light-induced facile modulation route for QD-dye conjugates. QD crystal violets conjugates (QD-CVs) were prepared and the crystal violet (CV) molecules on QD quenched the fluorescence efficiently. The fluorescence of QD-CVs showed a single cycle of emission burst as they go through three stages of (i) initially quenched "off" to (ii) photoactivated "on" as the result of chemical change of CVs induced by photoelectrons from QD and (iii) back to photodarkened "off" by radical-associated reactions. Multicolor on-demand photopatterning was demonstrated using QD-CV solid films. QD-CVs were introduced into cells, and excitation with visible light yielded photomodulation from "off" to "on" and "off" by nearly ten fold. Individual photoluminescence dynamics of QD-CVs was investigated using fluorescence correlation spectroscopy and single QD emission analysis, which revealed temporally stochastic photoactivations and photodarkenings. Exploiting the stochastic fluorescence burst of QD-CVs, simultaneous multicolor super-resolution localizations were demonstrated.
光开关或量子点（QD）的调制在包括显示、存储和超分辨率成像在内的许多领域都很有前景。然而，这种调制主要依赖于 QD 附近共轭分子的光调制，这通常需要在 UV 下使用高能光子的高功率。我们报告了一种用于 QD-染料偶联物的可见光诱导的简便调制途径。制备了量子点菘蓝素偶联物（QD-CV），量子点上的结晶紫（CV）分子有效地猝灭了荧光。由于 QD 光电电子诱导的 CV 化学变化，QD-CV 经历了（i）最初猝灭的“关”到（ii）光激活的“开”，以及（iii）通过自由基相关反应回到光致暗的“关”三个阶段，其荧光表现出单循环发射爆发。使用 QD-CV 固体薄膜演示了多色按需光图案化。将 QD-CV 引入细胞中，用可见光激发可使荧光从“关”到“开”和“关”调节近十倍。使用荧光相关光谱和单个 QD 发射分析研究了 QD-CV 的单个荧光动力学，这揭示了时间上随机的光激活和光致暗化。利用 QD-CV 的随机荧光爆发，同时实现了多色超分辨率定位。
