Complex dielectric characterization of African trypanosomes for aptamer-based terahertz sensing applications

In this work, the first broadband dielectric characterization of African trypanosome parasites from 0.2 to 2.5 THz is presented as a foundation for future sensor applications in the mm- and THz-wave regime. After demonstrating detectability, the complex permittivity of a 5 micrometer thick parasite film is extracted directly from measurements of a terahertz time domain spectrometry setup using a chain matrix model based extraction algorithm. Results show lack of specific resonances but a moderate relative permittivity above 2.4 at low loss. Furthermore, an area raster scan of the permittivity is performed to evaluate the parameter stability over larger surfaces.