| dc.description.abstract | Terahertz (THz) spectroscopy is a non-ionizing technique that is emerging as a promising method for characterising biomaterials and early cancer detection. However, it has limitations in detecting low analyte concentrations. To overcome this limitation, THz plasmonic-like metasurfaces have been proposed. This thesis discusses four contributions related to THz spectroscopy and THz plasmonic-like metasurfaces. The thesis first explores recent experimental initiatives to improve thin-film sensing and particularly early cancer detection using THz plasmonic-like metasensors with various resonance phenomena. This analysis can be used to develop innovative metasurface biosensors in the future. Next, it is examined how anti-cancer drug intervention changes THz spectra to aid in the study of pharmaceuticals. Using basal cell carcinoma (BCC) as an example, a 3D organotypic model was cultured to investigate the THz electromagnetic (EM) characteristics of treated and untreated tumors at different stages. An advanced optimization approach is also proposed to compute the parameters of the double Debye (DD) dielectric model to distinguish between different tissues. Furthermore, it is investigated how the aggressiveness level of tumors affects the outcome of treatment. By comparing THz spectroscopy of two stem cell lines of oral squamous cell carcinoma (OSCC) at various stages and with different degrees of aggressiveness, the effectiveness of treatment was observed. Finally, the potential of THz plasmonic-like metasurfaces for cancer cell discrimination, specifically focusing on high quality-factor (Q-factor) electromagnetically induced transparency-like (EIT-like) metasurfaces is investigated. An ultrasensitive THz EIT-like metasurface based on asymmetric metallic resonators on an extremely thin and flexible dielectric substrate is created. Moreover, a combinational theoretical sensitivity analysis is presented. Also, the metasurface's response to the switchover of healthy cells with malignant cells and its response to an increase in cancerous cells is observed. The findings could present new prospects for fast, simple, and inexpensive biosensing. Lastly, the thesis outlines a roadmap for future research endeavors to address the remaining challenges in THz spectroscopy and metasurfaces for biological material characterization and sensing. | en_US |
