通过具有光学涡旋的四波混合干涉测量术对单个等离子体纳米颗粒的无背景3D纳米定位和亚纳米不对称检测
Background-free 3D nanometric localisation and sub-nm asymmetry detection of single plasmonic nanoparticles by four-wave mixing interferometry with optical vortices
摘要：
使用光学显微镜跟踪单个纳米颗粒是一种功能强大的技术，在生物学、化学和材料科学中具有许多应用。尽管取得了重大进展，但在散射环境中以纳米位置精度定位物体仍然具有挑战性。实现对比度的应用方法主要是基于荧光的，在激发态寿命以及光漂白引起的发射光子通量中具有基本限制。此外，迄今为止报道的每一种定位方法都需要从多个空间点采集信号，因此速度受到限制。在这里，我们展示了一种新的四波混频干涉测量技术，其中一个单一的非荧光金纳米粒子的位置确定优于20 nm的平面精度和1 nm轴向从快速单点采集测量，通过利用光学涡旋。该技术还对仅0.5%纵横比的粒子不对称性（对应于单个金原子层）以及粒子取向具有独特的敏感性，并且即使在生物细胞内，检测也是无背景的。这种方法开辟了在复杂的3D架构中解开单粒子贩运的新方法。
英文摘要：
Single nanoparticle tracking using optical microscopy is a powerful technique with many applications in biology, chemistry and material sciences. Despite significant advances, localising objects with nanometric position accuracy in a scattering environment remains challenging. Applied methods to achieve contrast are dominantly fluorescence based, with fundamental limits in the emitted photon fluxes arising from the excited-state lifetime as well as photobleaching. Furthermore, every localisation method reported to date requires signal acquisition from multiple spatial points, with consequent speed limitations. Here, we show a new four-wave mixing interferometry technique, whereby the position of a single non-fluorescing gold nanoparticle is determined with better than 20 nm accuracy in plane and 1 nm axially from rapid single-point acquisition measurements by exploiting optical vortices. The technique is also uniquely sensitive to particle asymmetries of only 0.5% aspect ratio, corresponding to a single atomic layer of gold, as well as particle orientation, and the detection is background-free even inside biological cells. This method opens new ways of of unraveling single-particle trafficking within complex 3D architectures.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
