Proceedings Article | 18 November 2019
Proc. SPIE. 11196, Infrared, Millimeter-Wave, and Terahertz Technologies VI
KEYWORDS: Metamaterials, Biosensors, Polarization, Terahertz radiation, Biosensing, Cancer, Biomedical optics, Flow cytometry, Split ring resonators, Lung cancer
The rapid detection of cancer cells is crucial for clinical diagnosis in biomedical field. The traditional flow cytometry (FC) in visible band, a fluorescence-labelling detection, gives rise to the complicated sample preparation and the irrecoverable antibody consumption; it blocks the development toward a convenient detection platform with fast, inexpensive and non-labelling. Here, a specifically designed metamaterial based on split ring resonators (SRRs) is proposed. Such metamaterial operating in terahertz (THz) range exhibits polarization-dependent resonances, which are observed both in experiments and simulations. Additionally, the biosensing property of the metamaterial is investigated. On metamaterial surfaces, the lung cancer cells A549 are cultured. Under the irradiation of x-polarized THz waves, it is found that for the cell concentrations from 1×10<sup>5</sup> cells/ml to 5×10<sup>5</sup> cells/ml, the maximum frequency shift Δ<i>f</i> (the frequency difference between measured sample and bare one) at 2.24 THz increases from 15 GHz to 137 GHz, respectively. Such results also imply that a larger cell concentration leads to a higher frequency shift. Subsequently, the samples are further measured at different polarization angles. The results show that for cell concentration of 5×10<sup>5</sup> cells/ml, the Δ<i>f</i> exhibits the same value of 130 GHz when polarization angle equals 30° and 150°, and 15 GHz when polarization angle equals 60° and 120°. Our proposed metamaterial may supply a potential biosensing method for the detection of cancer cells, exhibiting a new insight toward the cancer cell biosensing with certain information of polarization response.
