Biomedical Sensing with Conductively Coupled Terahertz Metamaterial Resonators

Metamaterials that can support ultrasharp resonances using conductively coupled split ring resonators are potential candidates for designing label-free biomedical sensors. The sharp spectral response, as well as the ability to confine the field, increases the interaction between the electromagnetic field and unidentified analytes. A sensitivity level of 3 × 10⁴ nm/RIU/unit-volume is achieved when the whole area of the sensor is covered with the analyte. More interestingly, we demonstrate that the sensitivity can be significantly enhanced by a factor of 19 reaching a value of 5.7 × 10⁵ nm/RIU/unit-volume when selected spots are covered with the analyte. These results will pave the way for designing practical biomedical sensors in the terahertz frequency range.