Abstract-High precision dual-modulation differential terahertz ATR sensor for liquid measurements

 

Xiujun Zheng, Thomas Gevart,  Guilhem Gallot, 

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-46-16-4045

We describe a highly sensitive and stable quantum-cascade-laser-based attenuated total reflection (ATR) terahertz sensor for the detection of very low concentration solutions, using a dual-modulation differential approach and ATR geometry. This sensor offers a very high dynamic range and a long-term stability of 40 dB, which extends the potential of terahertz radiation for the analysis of liquid and biological samples. The performance is illustrated by measurements on standard solutions of ions, sugars, and proteins, for concentrations down to 1 µM.

© 2021 Optical Society of America

Abstract-Quantitative measurement of permeabilization of living cells by terahertz attenuated total reflection

Marianne Grognot¹ and Guilhem Gallot^1,a)
 HIDE AFFILIATIONS
1 Laboratoire Optique et Biosciences, Ecole Polytechnique, CNRS UMR7645, 91128 Palaiseau, France and INSERM U1182, 91128 Palaiseau, France
a) Author to whom correspondence should be addressed. Electronic mail:Guilhem.Gallot@polytechnique.edu.
Appl. Phys. Lett. 107, 103702 (2015); http://dx.doi.org/10.1063/1.4930168

http://scitation.aip.org/content/aip/journal/apl/107/10/10.1063/1.4930168

Using Attenuated Total Reflection imaging technique in the terahertz domain, we demonstrate non-invasive, non-staining real time measurements of cytoplasm leakage during permeabilization of epithelial cells by saponin. The terahertz signal is mostly sensitive to the intracellular protein concentration in the cells, in a very good agreement with standard bicinchoninic acid protein measurements. It opens the way to in situ real time dynamics of protein content and permeabilization in live cells