Quantitative Photophysics of Photoluminescent and Scintillating Nanoparticles

光致发光和闪烁纳米颗粒的定量光物理学

• 批准号: 312970-2013
• 负责人: Nadeau, Jay
• 金额: $ 2.15万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571804
• 关键词: Quantitative; Photophysics; Photoluminescent; Scintillating; Nanoparticles

Quantum dots (QDs) are fluorescent crystals of semiconductor materials (such as cadmium selenide, CdSe) that range from ~ 2 to 5 nm in diameter. This is less than 1/1000th the diameter of a typical living cell. QDs are capped with active molecules that enable them to remain in a stable suspension in water or other solutions. The energy and reactivity of QDs--determined by the material, capping agent, and size--determine the ability of a QD to transfer electrons to, or accept electrons from, other molecules in the solution. This electron transfer is very important for a large variety of applications and problems. Unwanted electron transfer can damage or kill biological tissue. Since it happens on the nanoscale, damage can occur deep inside cells, including the nucleus. On the other hand, electron transfer can be used to kill unwanted cells, such as cancer cells or bacteria. Transferring of electrons from QDs to other materials also allows QDs to be used as materials for solar cells, although currently the process is not well-enough understood to create high-efficiency materials. In our recent work we used a mathematical model to describe the fluorescence properties of QDs in the presence of electron-donating molecules. This model helped describe the mechanisms of QD fluorescence and electron transfer, and also provided insight into the off-on "blinking" seen in individual QDs. Our goals for this proposal are to extend and develop this model to provide a general quantitative photophysical description of QD fluorescence and blinking, with a particular emphasis on QDs in water exposed to electron-donating molecules. We will also expand to study other types of nanoparticles, such as those that emit luminescence under X-ray instead of visible light illumination (radioluminescent nanoparticles). This research will provide a framework useful to all scientists working with nanoparticle photophysics in biomedical or alternative energy applications. Our laboratory's long-term goals are to use these results to create anti-bacterial and anti-cancer agents based upon nanoparticles. These agents will be specifically targeted to the cancer or pathogen, and so show lower toxicity to healthy cells than many chemotherapy drugs.

量子点 (QD) 是半导体材料（例如硒化镉、CdSe）的荧光晶体，直径范围为 2 至 5 nm。这小于典型活细胞直径的 1/1000。量子点被活性分子覆盖，使它们能够在水或其他溶液中保持稳定的悬浮液。量子点的能量和反应性（由材料、封端剂和尺寸决定）决定了量子点将电子转移到溶液中其他分子或从溶液中其他分子接受电子的能力。这种电子转移对于多种应用和问题都非常重要。不需要的电子转移会损坏或杀死生物组织。由于它发生在纳米尺度上，损伤可能发生在细胞深处，包括细胞核。另一方面，电子转移可用于杀死不需要的细胞，例如癌细胞或细菌。将电子从量子点转移到其他材料也使得量子点可以用作太阳能电池的材料，尽管目前对于创建高效材料的过程还没有足够的了解。 在我们最近的工作中，我们使用数学模型来描述存在电子供给分子的情况下量子点的荧光特性。该模型有助于描述量子点荧光和电子转移的机制，并且还提供了对单个量子点中所见的开关“闪烁”的深入了解。我们此提案的目标是扩展和开发该模型，以提供 QD 荧光和闪烁的一般定量光物理描述，特别强调暴露于电子供给分子的水中的 QD。我们还将扩展研究其他类型的纳米颗粒，例如那些在 X 射线而不是可见光照射下发射发光的纳米颗粒（辐射发光纳米颗粒）。 这项研究将为所有在生物医学或替代能源应用中研究纳米粒子光物理学的科学家提供一个有用的框架。我们实验室的长期目标是利用这些结果来制造基于纳米粒子的抗菌和抗癌药物。这些药物将专门针对癌症或病原体，因此对健康细胞的毒性比许多化疗药物更低。