Pushing Optical Virus Detection to a Single Particle through a High- Q Quasi-bound State in the Continuum in an All-dielectric Metasurface

Zonglin Li; Mingxin Xie; Guozheng Nie; Junhui Wang; Lujun Huang

doi:10.1021/acs.jpclett.3c02763

Pushing Optical Virus Detection to a Single Particle through a High- Q Quasi-bound State in the Continuum in an All-dielectric Metasurface

J Phys Chem Lett. 2023 Dec 7;14(48):10762-10768. doi: 10.1021/acs.jpclett.3c02763. Epub 2023 Nov 27.

Authors

Zonglin Li^{1

2}, Mingxin Xie³, Guozheng Nie^{1

2

3}, Junhui Wang¹, Lujun Huang⁴

Affiliations

¹ School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China.
² Hunan Provincial Key Laboratory of Intelligent Sensors and New Sensor Materials, Xiangtan 411201, Hunan, China.
³ School of Microelectronics and Physics, Hunan University of Technology and Business, Changsha 410205, China.
⁴ School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.

PMID: 38010952
DOI: 10.1021/acs.jpclett.3c02763

Abstract

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-Q qBIC, the figure of merit (FOM) of the biosensor is up to 2136.35 RIU^-1. Futhermore, we demonstrated that such a high-Q 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.