基于 Fano 共振增强双光子荧光的不对称等离子体六聚体对单蛋白的传感。

Single protein sensing with asymmetric plasmonic hexamer via Fano resonance enhanced two-photon luminescence.

机构信息

College of Electronic Engineering, South China Agricultural University, Guangzhou, 510642, P.R. China.

Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou 510632, P.R. China.

出版信息

Nanoscale. 2015 Dec 28;7(48):20405-13. doi: 10.1039/c5nr04118j.

DOI:10.1039/c5nr04118j

PMID:26451715

Abstract

Fano resonances in plasmonic systems have been proved to facilitate various sensing applications in the nanoscale. In this work, we propose an experimental scheme to realize a single protein sensing by utilizing its two-photon luminescence enhanced by a plasmonic Fano resonance system. The asymmetric gold hexamer supporting polarization-dependent Fano resonances and plasmonic modes without in-plane rotational symmetry is used as a referenced spatial coordinate for bio-sensing. We demonstrate via the full-vectorial three-dimensional simulation that the moving direction and the spatial location of a protein can be detected via its two-photon luminescence, which benefits from the resonant near-field interaction with the electromagnetic hot-spots. The sensitivity to changes in position of our method is substantially better compared with the conventional linear sensing approach. Our strategy would facilitate the sensing, tracking and imaging of a single biomolecule in deep sub-wavelength scale and with a small optical extinction cross-section.

摘要

在纳米尺度上，表面等离激元系统中的 Fano 共振已被证明可以促进各种传感应用。在这项工作中，我们提出了一种实验方案，利用等离子体 Fano 共振系统增强的双光子荧光来实现单个蛋白质的传感。不对称的金六聚体支持偏振相关的 Fano 共振和没有面内旋转对称性的等离子体模式，被用作生物传感的参考空间坐标。我们通过全矢量三维模拟证明，通过双光子荧光可以检测蛋白质的运动方向和空间位置，这得益于与电磁热点的共振近场相互作用。与传统的线性传感方法相比，我们的方法对位置变化的灵敏度有了显著提高。我们的策略将有助于在深亚波长尺度和小光消光截面下对单个生物分子进行传感、跟踪和成像。