Inspired by the human nose, e-noses are promising tools for the detection and analysis of volatile organic compounds (VOCs), often considered as responsible for olfactory pollution, and more recently discovered to be potential biomarkers of certain diseases such as cancer. Currently, systems based on polymers or inorganic materials are effective in terms of sensitivity, but often suffer from a low selectivity.
To improve their performance, scientists are particularly interested in the design of more stable biological materials such as peptide. Why this choice? First of all, because peptides are analogues of the proteins that participate in the recognition of odors in the human nose, but with a greater stability. Moreover, with the 21 amino acids, it is possible to design a great diversity of peptides with selective interactions for VOCs and thus offer e-noses better performance in terms of VOC recognition and discrimination.
In this context, a team at IRIG ^* has just designed original hybrid nanostructures by self-assembly of a surfactant-like peptide (Cys-Gly-Gly-Gly-Gly-Gly-Gly-Gly). Thanks to a simple spotting process using a spotter robot, they then succeeded in depositing them on a chip. In such a way, they obtained peptide hybrid nanostructures with controlled morphology and varied physico-chemical properties, which play a decisive role in the selectivity of VOC detection by the obtained e-nose.

The performances of such an e-nose are excellent with detection limits less than 1 part per billion by volume (ppbv) for hexanoic acid and 6 ppbv for phenol, two biomarkers of oesogastric cancers. This work was recently published in the journal ACS Nano.


Exploration into the nanoscopic world of biohybrid surfaces designed for the detection and discrimination of volatile organic compounds.
© Jonathan S. Weerakkody