E-Tongue, a patent-pending technology, is comprised of a silicon-based interdigitated electrode (IDE) array with nanostructured materials that can detect biomolecules and chemical compounds in a liquid sample.

Chemicals and biological species — such as amino acids, DNA, minerals, salts, and dissolved organic volatiles in water — may be found in liquids but some of them potentially are undetectable in gas. Thus, it may be useful to test certain bodily fluids for the presence of one or more target components, such as troponin or glucose, that may also not be as efficiently detectable in gas or liquid when utilizing existing technologies available in the market.

The E-Tongue technology is comprised of a variety of nanostructure materials that undergo a change in electrical properties, such as resistance or current, when biomolecules become bound to them. The measured electrical signal is processed through signal processing algorithms to provide interpretable results. The technology adopts a novel approach where analytes are not detected using highly specific target receptor but rather it utilizes an array of low-specificity sensors that yields electrical signals that act as signatures specific to the molecules present.

The technology provides a sensing platform for liquid samples to detect the presence of target components. This invention not only takes relatively little time for detection and is quantitatively specific for identifying the presence of one or more target components of a liquid, but also uses a minimum number of chemical or physical tests that can be performed simultaneously or sequentially.

E-Tongue has been used for liquid amino acid detection in which the sensing materials are unmodified or carboxylic-acid-group-modified carbon nano-tubes (though not exclusively limited to these two). These sensing materials can be expanded to use other materials as well as long as they are able to detect and provide sensitivity to the amino acid target component. Two amino acids, Glycine and Lysine, have been used as target molecules for detection, with sodium chloride solution acting as the reference sample.

The E-Tongue technology, a compact tool for target component detection, has an inherent advantage as it utilizes and expands the matured E-Nose technology platform and electronics.

NASA is actively seeking licensees to commercialize this technology. Please contact NASA’s Licensing Concierge at This email address is being protected from spambots. You need JavaScript enabled to view it. or call us at 202-358-7432 to initiate licensing discussions. Follow this link here  for more information.


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This article first appeared in the November, 2020 issue of Tech Briefs Magazine.

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