All-Dielectric Metasurface for Sensing Microcystin-LR

Abstract

Sensing Microcystin-LR (MC-LR) is an important issue for environmental monitoring, as the MC-LR is a common toxic pollutant found in freshwater bodies. The demand for sensitive detection method of MC-LR at low concentrations can be addressed by metasurface-based sensors, which are feasible and highly efficient. Here, we demonstrate an all-dielectric metasurface for sensing MC-LR. Its working principle is based on quasi-bound states in the continuum mode (QBIC), and it manifests a high-quality factor and high sensitivity. The dielectric metasurface can detect a small change in the refractive index of the surrounding environment with a quality factor of ~170 and a sensitivity of ~788 nm/RIU. MC-LR can be specifically identified in mixed water with a concentration limit of as low as 0.002 μg/L by a specific recognition technique for combined antigen and antibody. Furthermore, the demonstrated detection of MC-LR can be extended to the identification and monitoring of other analytes, such as viruses, and the designed dielectric metasurface can serve as a monitor platform with high sensitivity and high specific recognition capability.

Silicon Pillar Array-Based Terahertz Metamaterial Biosensor for Ultrasensitive Tumor Markers Detection

“…In this work, we designed and fabricated a dielectric metamaterial biosensor based on a silicon pillar array used for the detection of CA125 and HER2. The limit of detection (LOD) of this biosensor is lower than those of the gold nanobump arrays (LOD is about 20 ng/mL) and elliptic silicon disk-pair periodic arrays (LOD is about 0.002 g/L) and comparable to metal split-ring-resonators (LOD is about 0.1 ng/mL), indicating a promising sensing platform for cancer early diagnosis.…”

Recent advances in strongly resonant and gradient all-dielectric metasurfaces

“…In terms of biomarker sensing, the metasurface featured a sensitivity of 2 nm/nM and a limit of detection of 0.7 ng/mL, demonstrating the capacity of integrating the proposed CMOS-compatible metasurfaces in lab-onchip components for biosensing and diagnosis. In a similar approach, a SOI metasurface of titled nanoellipsoids functionalized for the detection of the biotoxin microcystin-LR (MC-LR) yielded a bulk sensitivity S = 788 nm/RIU, measured Q ∼ 170 (FoM∼ 100) and a very low detection limit for MC-LC of 0.002 ng/mL 91 . Label-free biosensing of DNA was demonstrated by functionalizing an A-BIC-SiN metasurface, detecting a concentration of 20 molecules/µm 2 paving the way for single-molecule regime 92 .…”

“…In a similar approach, a SOI metasurface of the titled nanoellipsoids functionalized for the detection of the biotoxin microcystin-LR (MC-LR) yielded a bulk sensitivity S = 788 nm RIU −1 , measured Q ∼ 170 (FoM ∼ 100) and a very low detection limit for MC-LC of 0.002 ng mL −1 . 91 Label-free biosensing of DNA was demonstrated by functionalizing an A-BIC-SiN metasurface, detecting a concentration of 20 mol μm −2 paving the way for a single-molecule regime. 92 Moreover, Wang et al 93 introduced a new type of Si-on-glass qBIC metasurface composed of asymmetric crescent-shapes meta-atoms, experimentally measuring a bulk sensitivity of 326 nm RIU −1 for a Q ∼ 120, as well as biomolecular layer sensing of streptavidin at sub-nM concentrations after biotin functionalization of the metasurface.…”

An All-Dielectric Metamaterial Terahertz Biosensor for Cytokine Detection

“…In this work, we designed and fabricated a dielectric metamaterial biosensor using a bonding process, so the dielectric layer is monocrystalline silicon and it avoids the electron beam lithography (EBL) exposure process, which enhances device reliability, reduces preparation costs and facilitates mass production. The limit of detection (LOD) of our device is about 100 pg/mL, which is lower than that of the gold nanobump arrays (LOD is about 20 ng/mL) [ 9 ] and the elliptic silicon disk-pair periodic arrays (LOD is about 0.002 g/L) [ 10 ] and is comparable to that of metal split-ring resonators (LOD is about 0.1 ng/mL) [ 11 ]. This study provides a feasible option for clinical CRS detection.…”