发光二极管激发的稀土上转换发光纳米材料的制备及生物成像应用

项目名称： 发光二极管激发的稀土上转换发光纳米材料的制备及生物成像应用

项目编号： No.21503054

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 分析化学

项目作者： 钟业腾

作者单位： 国家纳米科学中心

项目金额： 21万元

中文摘要： 稀土上转换发光纳米材料作为一类新兴的生物荧光探针材料，由于其独特的反-斯托克斯位移发光特性，使其在应用至生物医学成像时具有诸多优势。然而其较低的上转换发光效率，使得具有足够强度的上转换发光以及基于此的各类生物医学应用，通常只能在激光光源的激发下完成。本项目采用发光二极管（LED）代替激光作为激发光源。为了实现LED激发下的明亮上转换发光，本项目选择新型的钕离子敏化的稀土上转换发光纳米颗粒为研究对象，通过解决钕离子到镱离子的能量转移最优化以及激发态能量在镱离子介质中的迁移效率最大化这两个关键问题，显著提高该上转换发光探针在低功率光源激发下的发光效率。该LED激发的上转换发光探针应用于体外细胞标记以及体内活体成像上，可以提高生物安全性，降低设备成本，提高使用寿命。本项目借助LED光源独有的封装与阵列技术，设计新颖的便携式检测设备，进一步拓展上转换发光材料在生物医学领域的应用。

中文关键词： 纳米技术；生物成像；荧光探针；上转换发光；稀土

英文摘要： Rare-earth upconversion nanoprobes (UCNPs) have been widely investigated for bioimaging due to their unique Anti-Stokes shift properties that enable the conversion of low-energy photons into high-energy photons via multiphoton processes. To date, UCNPs are generally excited by laser devices for upconversion luminescence. However, the potential radiation risk, high price, limited life time and complex design of laser systems hinder the further application of the UCNPs. As an alternative, light-emitting diode (LED) holds great promise as an excitation source for bioimaging because of many inherent advantages. However, no photoluminescence upconversion has been reported upon LED excitation mainly due to the low upconversion efficiency of UCNPs and insufficient power density of LED. Base on the Nd-sensitized UCNPs (Nd-UCNPs), the energy transfer from Nd to Yb ions and excitation energy migration through Yb sublattice are optimized to largely enhance the upconversion luminescence of the Nd-UCNPs, and 740-nm LED lamp is adopted to excite these Nd-UCNPs. With the benefit of these novel LED-excited Nd-UCNPs, in-vivo and in-vitro bioimaging without high-costed laser or mercury vapour light sources are developed. Moreover, the using of LED as the excitation source enable the flexible LED array design towards novel strategies for the application and performance of the upconversion nanoprobes. Thus economic handheld LEDs devices are further developed for semi-quantitative visual measurement of UCNPs.

英文关键词： nanotechnology;bioimaging;fluorescence probe;upconversion luminescence;rare earth