Sensing method based on the reflective property of a thin metallic mesh device in the terahertz region

We demonstrate a new biosensing method using the reflective property of a metallic mesh device (MMD). The MMD can work as a band-pass filter in the terahertz (THz) region and its sensing mechanism is attributed to localization of the electromagnetic field on the surface of the device due to the periodic structure. The refractive index of a liquid sample can be estimated by calculating the shift in the reflectance spectrum before and after the sample is attached to the device. The results indicate that the reflection measurement method is effective for solution measurement and also MMDs could function as sensors for detecting the affinity of its near-surface property for water.