Abstract

Detections of biological substances such as fungi, bacteria, and virus have been of particular interests in the terahertz (THz) frequency range for the purpose of food and security inspection. There has been hardly any progress since they are mostly transparent against THz waves. On the other hand, metamaterials have been studied extensively to develop useful biosensors. In particular, THz metamaterials have gap structures typically with the size of 3 μm which is compatible with the sizes of the microorganisms. Here, we show that THz metamaterials can work as an efficient sensor for sensing microorganisms such as fungi, yeasts and bacteria [1]. A clear shift in the resonant frequency is observed following the deposition of microorganisms on the THz metamaterials (Fig. 1a), and it rises up due to the change in the effective dielectric constant in a gap area of the metamaterials. Strong field localization and enhancement in the gap area enables us to detect the microorganisms with high sensitivity.

© 2015 IEEE