Li Zonglin, Xie Mingxin, Nie Guozheng, Wang Junhui, Huang Lujun
School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China.
Hunan Provincial Key Laboratory of Intelligent Sensors and New Sensor Materials, Xiangtan 411201, Hunan, China.
J Phys Chem Lett. 2023 Dec 7;14(48):10762-10768. doi: 10.1021/acs.jpclett.3c02763. Epub 2023 Nov 27.
Bound states in the continuum (BICs) have emerged as a powerful platform for boosting light-matter interactions because they provide an alternative way of realizing optical resonances with ultrahigh quality factors, accompanied by extreme field confinement. In this work, we realized an optical biosensor by harnessing a quasi-BIC (qBIC) supported by an all-dielectric metasurface with broken symmetry, whose unit cell is composed of a silicon cuboid with two asymmetric air holes. Thanks to the excellent field confinement within the air gap of a metasurface enabled by such a high- qBIC, the figure of merit (FOM) of the biosensor is up to 2136.35 RIU. Futhermore, we demonstrated that such a high- metasurface can push the detection limit to a few virus particles. Our results may find exciting applications in extreme biochemical sensing like COVID-19 with ultralow concentrations.
连续域束缚态（BICs）已成为增强光与物质相互作用的强大平台，因为它们提供了一种实现具有超高品质因数的光学共振的替代方法，同时伴随着极端的场限制。在这项工作中，我们利用由具有破缺对称性的全介质超表面支持的准BIC（qBIC）实现了一种光学生物传感器，其单元由一个带有两个不对称气孔的硅长方体组成。由于这种高qBIC在超表面气隙内实现了出色的场限制，该生物传感器的品质因数（FOM）高达2136.35 RIU。此外，我们证明了这种高超表面可以将检测限降低到几个病毒颗粒。我们的结果可能在诸如超低浓度COVID-19等极端生化传感中找到令人兴奋的应用。
