Shin Kyujin, Jung Taeyoung, Lee Eunsang, Lee Gibok, Goh Yeongchang, Heo Junseok, Jung Minhyuk, Jo Eun-Jung, Lee Hohjai, Kim Min-Gon, Lee Kang Taek
Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea.
Phys Chem Chem Phys. 2017 Apr 12;19(15):9739-9744. doi: 10.1039/c7cp00918f.
Upconversion nanoparticles (UCNPs) have attracted enormous interest over the past few years because of their unique optical properties and potential for use in various applications such as bioimaging probes, biosensors, and light-harvesting materials for photovoltaics. The improvement of imaging resolution is one of the most important goals for UCNPs used in biological applications. Super-resolution imaging techniques that overcome the fundamental diffraction limit of light rely on the photochemistry of organic dyes or fluorescent proteins. Here we report our progress toward super-resolution microscopy with UCNPs. We found that the red emission (655 nm) of core/shell UCNPs with the structure NaYF:Yb,Er/NaYF could be modulated by emission depletion (ED) of the intermediate state that interacts resonantly with an infrared beam (1540 nm). In contrast, the green emission bands (525 and 545 nm) of the UCNPs were less affected by irradiation with the infrared beam. The origin of such distinct behaviors between the green and red emissions was attributed to their different photophysical pathways.
在过去几年中，上转换纳米粒子（UCNPs）因其独特的光学性质以及在生物成像探针、生物传感器和用于光伏的光捕获材料等各种应用中的潜在用途而引起了极大的关注。提高成像分辨率是UCNPs在生物应用中的最重要目标之一。克服光的基本衍射极限的超分辨率成像技术依赖于有机染料或荧光蛋白的光化学。在此，我们报告了我们在使用UCNPs进行超分辨率显微镜研究方面取得的进展。我们发现，具有NaYF:Yb,Er/NaYF结构的核壳UCNPs的红色发射（655nm）可通过与红外光束（1540nm）共振相互作用的中间态的发射损耗（ED）来调制。相比之下，UCNPs的绿色发射带（525和545nm）受红外光束照射的影响较小。绿色和红色发射之间这种明显行为的起源归因于它们不同的光物理途径。
