Fluorescent enhancement of the nitrogen vacancy center in nanoscale diamond for bioimaging applications

项目摘要/摘要 在这项工作中，沃尔科特实验室将开发用于功能化的化学方法 纳米金刚石，目的是通过增加氮空位中心的荧光率 等离子激元。我们正在集中我们的专业知识来了解高压高压下的化学反应- 加热金刚石表面，研究金刚石-金属纳米结构自组装的机理。 利用荧光纳米钻石(FND)进行生物成像的进展因缺乏强有力的化学物质而受到阻碍 来修改它们的表面。此外，还没有实现提高NVC荧光率的进展。总的来说， 这些挑战导致胶体稳定性差，染色方案靶向性差，而且没有简单的路线 以提高FND的发射率。我们将应对这些挑战，以推进表面化学 纳米级钻石，建立连贯的化学反应模型，并提高自组装效率 金属纳米结构。25-100 nm微晶中的氮空位中心显示出荧光 增强，但只有通过原子力显微镜乏味的移动这些结构，这是 与细胞成像不兼容。这项研究的一个主要目标是了解调整表面化学将如何 驱动自组装，介质层厚度如何影响荧光率和FND-金属的生产 具有用于生物成像的强健特性的构造。此外，我们设想在荧光中使用这些FND构造 胰腺癌细胞系的成像研究。 我们的目标包括基础研究和应用荧光成像研究。世界银行的目标是 建议的工作包括：1)用湿化学和气相化学对FND表面进行改性，(2) 改性FND在金属纳米结构组装中的应用及(3)FND的基本机理 用于成像应用的NVC荧光增强。我们的表面化学将专注于共价键 低Z元素的形成，如氮和硅氧化物到ND表面。为了探测地表，我们将 使用实验室和同步加速器光谱仪的重叠技术。技术包括 动态光散射、FTIR、波长相关X射线光电子能谱(XPS)和近边 X射线吸收精细结构(NEXAFS)。表面信息将被用来引导我们的化学物质 方法论和协议制定。然后，共价部分将作为分子锚驱动 它们的组装具有金属纳米结构，并生长金属壳。FND发射属性将是 用共聚焦显微镜研究以确定荧光率和辐射寿命。有限差分法 时间域模拟将指导我们的化学反应，并为NVC建立150倍增长的目标 荧光率。这项工作将对NVC用于磁性的基础和应用研究产生影响 以及电场成像、测温和长期生物成像应用。 Pi-Wolcott是钻石表面化学和使用纳米颗粒进行生物染色的专家。这 该项目将得到与斯坦福大学纳米材料专家尼古拉斯·梅洛什教授的积极合作支持 斯坦福大学和表面科学家丹尼斯·诺德伦德博士在斯坦福同步辐射光源(SSRL)工作。 圣何塞州立大学(SJSU)位于旧金山湾区的黄金地段为科学提供了独特的机会 将在附近的研究中心完成，如SSRL和劳伦斯伯克利的分子铸造厂 国家实验室。上海州立大学沃尔科特实验室的一支充满干劲的本科生研究团队 正在充分利用这种环境，并正在推进本提案的初步目标，详情请参阅 研究策略。

Project Summary/Abstract In this body of work the Wolcott laboratory will develop chemical methodologies for the functionalization of nanoscale diamond with the aim of increasing the fluorescent rate of the nitrogen vacancy center (NVC) via plasmonics. We are focusing our expertise to understand chemical reactivity at the high-pressure high- temperature diamond surface and investigate the mechanisms for diamond-metal nanostructure self-assembly. Advancements in bioimaging with fluorescent nanodiamonds (FNDs) are hindered by a lack of robust chemistry to modify their surface. Further, no advances for increasing the NVC fluorescent rate have been realized. In total, these challenges have resulted in poor colloidal stability, poor targeting in staining protocols and no simple routes to enhance FND emission rates. We will address these challenges to advance the surface chemistry of nanoscale diamond, build coherent models of chemical reactivity and increase the efficacy for self-assembly with metallic nanostructures. The nitrogen vacancy center in 25-100 nm crystallites have shown fluorescent enhancement, but only with tedious movement of these structures by atomic force microscopy which is incompatible with cell imaging. A major goal of the study is to understand how tuning the surface chemistry will drive self-assembly, how dielectric layer thickness effects fluorescent rates and the production of FND-metallic constructs with robust properties for bioimaging. Further, we envision using these FND constructs in fluorescent imaging studies with pancreatic cancer cell lines. Our aims include both fundamental studies and applied fluorescence imaging investigations. The goals of the proposed work include: 1) modification of the FND surface with wet chemical and gas phase chemistry, (2) application of the modified FND for metallic nanostructure assembly and (3) the fundamental mechanisms of NVC fluorescence enhancement for imaging applications. Our surface chemistry will focus on covalent bond formation of low-Z elements such as nitrogen and silicon oxide to the ND surface. To probe the surface we will use overlapping techniques that are laboratory and synchrotron-based spectroscopies. Techniques include dynamic light scattering, FTIR, wavelength dependent X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS). Surface information will then be used to direct our chemical methodology and protocol development. The covalent moieties will then act as the molecular anchors to drive their assembly with metal nanostructures and to grow metallic shells. FND emission properties will be investigated with confocal microscopy to determine fluorescent rates and radiative lifetimes. Finite-difference time-domain simulations will guide our chemistry and establishes a target of a 150x fold increase for the NVC fluorescent rate. This work will impact fundamental and applied research where the NVC is used for magnetic and electric field imaging, thermometry and long-term bioimaging applications. PI-Wolcott is an expert in diamond surface chemistry and the use of nanoparticles for biological staining. This project will be supported by the active collaborations with nanomaterial expert Prof. Nicholas Melosh at Stanford University and surface scientist Dr. Dennis Nordlund at the Stanford Synchrotron Radiation Lightsource (SSRL). The prime location of San Jose State University (SJSU) in the Bay Area provides unique opportunities for science to be accomplished at near-by research centers such as SSRL and The Molecular Foundry at Lawrence Berkeley National Laboratory. A highly motivated team of undergraduate researchers in the Wolcott laboratory at SJSU are taking full advantage of this environment and are advancing the initial aims of this proposal as detailed in the Research Strategy.