Plasmonic hotspots for single-molecule biophysics

单分子生物物理学的等离子体热点

• 批准号: 267681426
• 负责人: Professor Dr. Philip Tinnefeld
• 金额: --
• 依托单位: Department Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/267681426?language=en
• 关键词: Plasmonic; hotspots; single; molecule; biophysics

Supported by the DFG, the Acuna and Tinnefeld labs developed and characterized single-molecule fluorescence from optical antennas. These optical antennas are comprised of two noble metal nanoparticles with a defined gap that are self-assembled using DNA origami nanostructures as scaffold. In addition to the structural organization of nanoparticles, the DNA origami enables placing specific molecular moieties in the antenna’s hotspot. After clarifying many spectroscopic characteristics of fluorescent dyes placed in the optical antennas including fluorescence enhancement up to 5000 fold and first proofs of biocompatibility, the Tinnefeld lab now aims at exploring DNA origami nanoantennas as novel detection volume in single-molecule biophysics. The higher achievable count rates and increased photostability of the dye molecules in the hotspot will be used to study fast biomolecular processes with increased time resolution. DNA origami nanoantennas will be optimized for reduced steric hindrance and single-molecule FRET from the red spectral region to the near infrared will be established adapted to the spectral profile of the nanoantennas. Biomolecular systems of interest will be placed in the antenna’s hotspot and fast conformational changes of proteins will be studied and transition path times of binding induced protein folding as well as of nucleic acid hairpins will be revealed. Above that, a DNA strand displacement tug-of-war will be visualized at single-nucleotide resolution hoping to reveal subtle sequence dependent kinetic variations such as those occurring in epigenetic nucleotide modifications. In summary, we aim at establishing DNA origami antennas as new detection volume of single-molecule research opening a novel window into fast biomolecular processes.

在DFG的支持下，Acuna和Tinnefeld实验室开发并表征了来自光学天线的单分子荧光。这些光学天线由两个具有确定间隙的贵金属纳米粒子组成，它们使用DNA折纸纳米结构作为支架进行自组装。除了纳米颗粒的结构组织外，DNA折纸还可以将特定的分子部分放置在天线的热点上。在澄清了放置在光学天线中的荧光染料的许多光谱特征，包括高达5000倍的荧光增强和生物相容性的第一个证据之后，Tinnefeld实验室现在的目标是探索DNA折纸纳米天线作为单分子生物物理学中新的检测体积。热点中染料分子更高的可实现计数率和更高的光稳定性将用于研究具有更高时间分辨率的快速生物分子过程。将对DNA折纸纳米天线进行优化，以降低空间位阻，并根据纳米天线的光谱分布建立从红光谱到近红外的单分子FRET。感兴趣的生物分子系统将被放置在天线的热点上，研究蛋白质的快速构象变化，揭示结合诱导的蛋白质折叠和核酸发夹的过渡路径时间。在此之上，DNA链位移拉锯战将在单核苷酸分辨率下可视化，希望揭示微妙的序列依赖动力学变化，如表观遗传核苷酸修饰中发生的变化。总之，我们的目标是建立DNA折纸天线作为单分子研究的新检测体，为快速生物分子过程打开新的窗口。