Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States.
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States.
J Phys Chem Lett. 2022 May 26;13(20):4520-4529. doi: 10.1021/acs.jpclett.1c04123. Epub 2022 May 16.
Plasmonic nano-objects have shown great potential in enhancing applications like biological/chemical sensing, light harvesting and energy transfer, and optical/quantum computing. Therefore, an extensive effort has been vested in optimizing plasmonic systems and exploiting their field enhancement properties. Super-resolution imaging with quantum dots (QDs) is a promising method to probe plasmonic near-fields but is hindered by the distortion of the QD radiation pattern. Here, we investigate the interaction between QDs and "L-shaped" gold nanoantennas and demonstrate both theoretically and experimentally that this strong interaction can induce polarization-dependent modifications to the apparent QD emission intensity, polarization, and localization. Based on FDTD simulations and polarization-modulated single-molecule microscopy, we show that the displacement of the emitter's localization is due to the position-dependent interference between the emitter and the induced dipole, and can be up to 100 nm. Our results help pave a pathway for higher precision plasmonic near-field mapping and its underlying applications.
等离子体纳米物体在增强生物/化学传感、光捕获和能量转移以及光学/量子计算等应用方面显示出巨大的潜力。因此，人们投入了大量的精力来优化等离子体系统并利用其场增强特性。利用量子点 (QD) 进行超分辨率成像是探测等离子体近场的一种很有前途的方法，但受到 QD 辐射模式失真的阻碍。在这里，我们研究了 QD 与“L 形”金纳米天线之间的相互作用，并从理论和实验上证明了这种强相互作用可以诱导对 QD 发射强度、偏振和定位的偏振相关修饰。基于 FDTD 模拟和偏振调制单分子显微镜，我们表明发射器的定位的位移是由于发射器和感应偶极子之间的位置相关干涉引起的，最大可达 100nm。我们的研究结果有助于为更高精度的等离子体近场测绘及其潜在应用铺平道路。
