Yin Yumeng, Trichet Aurélien A P, Qian Jiangrui, Smith Jason M
Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, United Kingdom.
J Phys Chem Lett. 2024 Dec 12;15(49):12105-12111. doi: 10.1021/acs.jpclett.4c02104. Epub 2024 Nov 27.
Shape measurement of single nanoparticles in fluids is an outstanding challenge with applications in characterizing synthetic functional nanoparticles and in early warning detection of rod-shaped pathogens in water supplies. Here we introduce a novel technique to measure the aspect ratio of rod-shaped particles by analyzing changes in the polarization state of a laser beam transmitted through an optical microcavity through which the particle diffuses. The resolution in aspect ratio measurement is found to be around 1%. Our work opens the new possibility of in situ and single-particle shape measurement, which has promising applications in nanoparticle characterization, water monitoring, and beyond.
测量流体中单个纳米颗粒的形状是一项极具挑战性的任务，它在合成功能纳米颗粒的表征以及供水系统中杆状病原体的早期预警检测等方面都有应用。在此，我们介绍一种新技术，通过分析激光束透过光学微腔（颗粒在其中扩散）时偏振态的变化来测量杆状颗粒的纵横比。发现纵横比测量的分辨率约为1%。我们的工作开启了原位和单颗粒形状测量的新可能性，这在纳米颗粒表征、水质监测及其他领域有着广阔的应用前景。
