Department of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States.
Department of Chemistry, University of California, Irvine, California 92697, United States.
Nano Lett. 2022 Aug 24;22(16):6685-6691. doi: 10.1021/acs.nanolett.2c02040. Epub 2022 Aug 12.
Surface-enhanced coherent anti-Stokes Raman scattering (SE-CARS) takes advantage of surface plasmon resonances supported on metallic nanostructures to amplify the coherent Raman response of target molecules. While these metallic antennas have found significant success in SE-CARS studies, photoinduced morphological changes to the nanoantenna under ultrafast excitation introduce significant hurdles in terms of stability and reproducilibty. These hurdles need to be overcome in order to establish SE-CARS as a reliable tool for rapid biomolecular sensing. Here, we address this challenge by performing molecular CARS measurements enhanced by nanoantennas made from high-index dielectric particles with more favorable thermal properties. We present the first experimental demonstration of enhanced molecular CARS signals observed at Si nanoantennas, which offer much improved thermal stability compared to their metallic counterparts.
表面增强相干反斯托克斯拉曼散射（SE-CARS）利用金属纳米结构上支持的表面等离激元共振来放大目标分子的相干拉曼响应。虽然这些金属天线在 SE-CARS 研究中取得了巨大的成功，但在超快激发下纳米天线的光诱导形态变化给稳定性和重现性带来了重大障碍。为了将 SE-CARS 确立为快速生物分子传感的可靠工具，需要克服这些障碍。在这里，我们通过对由具有更有利热性能的高折射率介电粒子制成的纳米天线进行分子 CARS 测量来解决这一挑战。我们首次实验证明了在 Si 纳米天线上观察到的增强分子 CARS 信号，与金属对应物相比，Si 纳米天线上的信号具有更好的热稳定性。
