40 GHz RF biosensor based on microwave coplanar waveguide transmission line for cancer cells (HepG2) dielectric characterization

This paper presents a 40-GHz RF biosensor that involves using a microwave coplanar waveguide (CPW) transmission line for the dielectric characterization of cancer cells (Hepatoma G2, HepG2). In the past, conventional resonator-based biosensors were designed to operate at a specific resonant peak; however, the dielectric sensitivity of the cells was restricted to a narrow bandwidth. To provide a very wide bandwidth (1–40 GHz), biosensors were based on a microwave CPW transmission line. The proposed biosensor can rapidly measure two frequency-dependent cell-based dielectric parameters of HepG2 cells, microwave attenuation (α(f)cell) and the dielectric constant (εr(f)cell), while removing the microwave parasitic effects (including the cultured medium and substrate materials). The proposed biosensor can be applied in postoperative cancer diagnosis. •We propose a new biosensor based on microwave coplanar waveguide transmission line.•We are the first to investigate the dielectric properties of HepG2 cells at a very wide bandwidth to 40 GHz.•The biosensor is to operate at microwave frequencies for detecting HepG2 cells in biomedical diagnosis.•The new approach is to removing microwave parasitic effects while the biosensor performs on-chip measurement.