稀土掺杂CaSc2O4纳米晶上转换荧光调制及其发光物理

项目名称： 稀土掺杂CaSc2O4纳米晶上转换荧光调制及其发光物理

项目编号： No.11504029

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 李静

作者单位： 长春工业大学

项目金额： 24万元

中文摘要： 荧光上转换纳米晶可望在示踪、成像等生物医用领域有重要应用。与效率最高的氟化物相比，氧化物具有更稳定的理化性质。新型氧化物钪酸钙声子能量仅540 cm-1, 显示出高效上转换荧光潜力。相对于典型高效上转换材料氧化钇，Tm/Yb掺杂钪酸钙体材料中Tm离子 800 nm发射增强3.5倍,与氟钇钠基质中强度相当。通过激活剂/敏化剂浓度、种类优化，表面修饰及核壳包覆等手段可对上转换荧光在可见光范围内进行调制并进一步提高荧光效率。然而目前尚未见有关适于生物应用钪酸钙纳米晶物理特性的报道。本项目针对钪酸钙纳米晶进行研究，拟采用湿化学法实现材料的可控合成及上转换性能优化。利用发光学原理及光谱技术手段,重点研究钪酸钙纳米晶发光性质、能量传递及动力学过程,揭示稀土离子在钪酸钙纳米晶中上转换荧光调制/增强的规律及物理机制。为研制出高效可控且颜色可调钪酸钙纳米晶,实现其在生物医学领域的广泛应用奠定材料与物理基础。

中文关键词： 上转换发光；稀土发光；能量传递；激光光谱学；钪酸钙

英文摘要： Upconversion luminescence (UCL) in rare earth ions doped crystals has played an important role on sensitive biological fluorescent labeling and medical imaging. Although the host material for achieving the most efficient UCL is fluoride，highly efficient UCL is still strongly expected in oxide materials for their stable chemical and thermal properties. The promising oxide host CaSc2O4 which attracts the attention owns a low cutoff phonon frequency of about 540 cm-1, exhibiting highly efficient upconversion luminescence. Compared with that in dopant concentration optimized Y2O3: Tm3+/Yb3+, the UCL around 800 nm of CaSc2O4: Tm3+/Yb3+ is enhanced by a factor of 3.5. The present UCL intensity at 800 nm matching the bio-optical window in CaSc2O4: Tm3+/Yb3+ is in principle comparable to that in NaYF4: Tm3+/Yb3+. The upconversion luminescence can be improved and spectral distribution can be modulated further via changing concentrations and species of doped lanthanide ions, surface modification of nanoparticles, core-shell structure etc.As far as we know,the UCL properties of CaSc2O4 nano-crystals for biological applications have not been demonstrated yet. Thus, this project is looking for novel chemistry method to achieve controlled synthesis and optimized luminescence of calcium scandate nano-crystals. Upconversion luminescence and energy transfer mechanism along with the dynamic processes of calcium scandate nano-crystals are investigated by means of electronic spectroscopy techniques including the emission and absorption spectroscopy, surface-enhanced Raman spectroscopy (SERS), etc. Clear and potent mechanisms and scenarios should be put forward to elucidate the upconversion modulated/enhanced luminescence. Much more importantly and valuably to be addressed, our proposal is aiming at establishing the physical and experimental basis of biological applications of calcium scandate nano-crystals which owns highly efficient and modulated UCL.

英文关键词： upconversion luminescence;lanthanide fluorescence;energy transfer;laser spectroscopy;calcium scandate