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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Dielectric nanohole array metasurface for high-resolution near-field sensing and imaging

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Conteduca, Donato [1] ; Barth, Isabel [1] ; Pitruzzello, Giampaolo [1] ; Reardon, Christopher P. [1] ; Martins, Emiliano R. [2] ; Krauss, Thomas F. [1]
Total Authors: 6
[1] Univ York, Dept Phys, Photon Grp, York, N Yorkshire - England
[2] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Elect & Comp Engn, Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: NATURE COMMUNICATIONS; v. 12, n. 1 JUN 2 2021.
Web of Science Citations: 1

Dielectric metasurfaces support resonances that are widely explored both for far-field wavefront shaping and for near-field sensing and imaging. Their design explores the interplay between localised and extended resonances, with a typical trade-off between Q-factor and light localisation; high Q-factors are desirable for refractive index sensing while localisation is desirable for imaging resolution. Here, we show that a dielectric metasurface consisting of a nanohole array in amorphous silicon provides a favourable trade-off between these requirements. We have designed and realised the metasurface to support two optical modes both with sharp Fano resonances that exhibit relatively high Q-factors and strong spatial confinement, thereby concurrently optimizing the device for both imaging and biochemical sensing. For the sensing application, we demonstrate a limit of detection (LOD) as low as 1pg/ml for Immunoglobulin G (IgG); for resonant imaging, we demonstrate a spatial resolution below 1 mu m and clearly resolve individual E. coli bacteria. The combined low LOD and high spatial resolution opens new opportunities for extending cellular studies into the realm of microbiology, e.g. for studying antimicrobial susceptibility. Dielectric metasurfaces have different Q-factor and light localisation requirements for sensing and imaging. Here, the authors present a dielectric metasurface, supporting two optical modes with sharp Fano resonances for high Q-factors and strong spatial confinement, allowing both sensing and imaging. (AU)

FAPESP's process: 20/00619-4 - Metasurfaces for imaging and sensing
Grantee:Emiliano Rezende Martins
Support type: Regular Research Grants