Water-Based Terahertz Metamaterial for Skin Cancer Detection Application

We present a highly sensitive detection of skin cancer using a novel water-based terahertz (THz) metamaterial (MM) and a semiconductor film. We apply the application of terahertz pulsed imaging in reflection geometry for the study of skin tissue and related cancers. As a refractive index (RI) sensing application of the proposed device, with placing different sensing materials in the biosensor design, the effective RI will also change that in turn leads to measuring the sensitivity of the biosensor to detect the normal skin and basal cell carcinoma. The RI figure of merit (FOM) value of the proposed device is much higher than that of the sensor using a semiconductor film to detect biomarkers in the literature. Significantly, the sensitivity increases by about 117 um/RIU and the RI FOM increases by more than 20.53. This results from a combination of size-related factors, leading to field enhancement accompanying strong field localization. We observed the resonance-frequency shift of the THz MM following the RI changing of the detected skin. The dip reflectance resonance has a blue shift for normal skin. Finally, we suggest that this water-based MM can be used to the control of the gene expression. The advantage of our design depends on two factors. First, we used the MM structure that has micro-scale, and the smaller the size of the structure, the more sensitive to the changes in the RI. Second, we used water in our structure, which is very well-suited to the human body, highly bio-absorbable and inexpensive, and abundantly found in nature.