Abstract-Single-cell terahertz spectral characteristics in simulated scattering near-field imaging mode

Jie Wang, Shihan Yan, Zaoxia Li, Ziyi Zang, Xingxing Lu, and Hong-Liang Cui

Schematic of the coupled tip–cell model system.

https://www.osapublishing.org/osac/abstract.cfm?URI=osac-3-8-2096

Spectral imaging of a single cell with terahertz (THz) wave is valuable in determination of its physiological state for cell-based precision diagnosis, as THz photon energy is in tune with the vibration-rotation and conformation related excitations of cellular material, and THz absorption is extremely sensitive to the state and degree of hydration of a cell. Because of the severe mismatch between the cell size and the THz wavelength, such imaging has to be carried out in the near-field modality. To make the design and performance assessment of a THz near-field spectral imager effective and systematic, we simulate the scattering THz near-field signals of tumor cells by strictly controlling cell model parameters with representative physiological states. The results demonstrate that the specific physiological characteristics from intracellular hydration state, nucleocytoplasmic ratio, and cell geometric morphology of tumor cells can be characterized quantitatively by their discrepant dielectric response in the THz band, correlating THz near-field scattering signal from a cell with the latter’s corresponding physicochemical state.

© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Single cell imaging with near‐field terahertz scanning microscopy

Zaoxia Li, Shihan Yan, Ziyi Zang, Guoshuai Geng, Zhongbo Yang, Jiang Li, Lihua Wang, Chunyan Yao, Hong‐Liang Cui, Chao Chang, Huabin Wang

https://onlinelibrary.wiley.com/doi/full/10.1111/cpr.12788

Objectives

Terahertz (THz)‐based imaging techniques hold great potential for biological and biomedical applications, which nevertheless are hampered by the low spatial resolution of conventional THz imaging systems. In this work, we report a high‐performance photoconductive antenna microprobe‐based near‐field THz time‐domain spectroscopy scanning microscope.

Materials and methods

A single watermelon pulp cell was prepared on a clean quartz slide and covered by a thin polyethylene film. The high performance near‐field THz microscope was developed based on a coherent THz time‐domain spectroscopy system coupled with a photoconductive antenna microprobe. The sample was imaged in transmission mode.

Results

We demonstrate the direct imaging of the morphology of single watermelon pulp cells in the natural dehydration process with our near‐field THz microscope.

Conclusions

Given the label‐free and non‐destructive nature of THz detection techniques, our near‐field microscopy‐based single‐cell imaging approach sheds new light on studying biological samples with THz.