Resonant microwave sensors for picoliter liquid characterization and nondestructive detection of single biological cells

Enthalten in
IEEE journal of electromagnetics, RF and microwaves in medicine and biology 
Volume
1
Issue
2
Start Page
98
End Page
104
Article Number
8239815
Citation
IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology 2 (1): 8239815, 98-104 (2017-12-01)
Publisher DOI
10.1109/JERM.2017.2787479
Scopus ID
2-s2.0-85061518086
Publisher
IEEE
The nondestructive characterization of small liquid volumes, as well as the detection of single biological cells, can lead to new insights for biomedical and biotechnological applications. The dielectric permittivity of the sample, which depends on the chemical composition, is detected using electromagnetic sensors in the microwave frequency range. The sensing system proposed here is based on resonant near-field sensors, which are combined with a microfluidic chip. The sample volume of a few picoliters enables single-cell measurements. A novel process featuring a biocompatible polymer material is used for fabricating the microfluidic channel for liquid samples. Two opposed sensing tips are integrated at the bottom of the channel to improve the sensitivity to small dielectric contrasts. They are connected to two resonators, which allows to simultaneously characterize the sample permittivity at two different frequencies. In a proof-of-principle experiment, single cells of the Chinese hamster ovary cell line are detected. This shows that the proposed sensing system is suitable for single-cell characterization due to its high sensitivity and spatial resolution. A potential biomedical application is the systematic investigation of various cell types and states to elucidate potential distinguishing characteristics.
Schlagworte
Biological cells
biosensors
microfluidics
microwave imaging
microwave sensors
permittivity
DDC Class
570: Biowissenschaften, Biologie
600: Technik
620: Ingenieurwissenschaften