12. Artificially structure your biosensor - 4CBLW00-12

Terahertz (THz) waves occupy a region of the electromagnetic spectrum between the mid-infrared and microwave regions. They have a longer wavelength, greater penetration depth and less scattering than visible and near-infrared waves. THz radiation has unique advantages, such as low emissivity, small photon energy, and no ionizing hazard to biological samples. THz spectroscopy and imaging techniques have been widely applied in various fields including biomedicine, food safety and agriculture. Surface resonance spectroscopy at metal-dielectric interfaces is used for the quantitative detection of bioactive substances, but the sensitivity is reduced in the THz range due to the high electrical conductivity of metals. The large negative permittivity of metals makes it difficult for electromagnetic fields to penetrate the metal, so methods to obtain a surface resonance in the THz range are urgently needed. Metamaterials, artificial electromagnetic media with subwavelength periodic structures, have overcome the lack of suitable materials in the terahertz range. The challenge is to develop artificial subwavelength electromagnetic structures based on metamaterials (different materials and structures, including metallic materials, non-metallic materials and hybrid material structures) to generate enhanced electric fields on the sensor surface under the action of the THz wave, enhancing the THz-matter interaction with the analyte and changing the spectral response.