A research team led by Prof. Shlomo Yitzchaik and Prof. Mattan Hurevich at the Hebrew University of Jerusalem has developed a gas-sensing platform that can separate mirror-image molecules in air a task that standard detectors rarely achieve. Working with researchers from the Technical University of Dresden and Friedrich Schiller University Jena, the group demonstrated a sensor that uses sugar-based receptor molecules attached to carbon nanotubes to detect subtle structural differences in volatile organic compounds.
Shitrit, A., Sukhran, Y., Tverdokhleb, N., Chen, L., Dianat, A., Gutierrez, R., Körbel, S., Croy, A., Cuniberti, G., Hurevich, M., & Yitzchaik, S. (2025). Monosaccharide‐Derived Enantioselectivity in SWCNT Chemoresistive VOC Sensing. Chemistry – A European Journal. https://doi.org/10.1002/chem.202502553
The challenge tackled by the team involves molecules known as enantiomers, which share the same chemical formula but differ in orientation, much like left and right hands. These small differences can have significant practical consequences. For example, the two mirror forms of compounds such as limonene or carvone smell different and behave differently in biological and industrial environments. Conventional gas sensors usually cannot distinguish between them because their chemical structures interact with surfaces in nearly the same way.
The researchers addressed this limitation by designing custom sugar-derived receptors and binding them to individual carbon nanotube sensing elements. The sugars form a precise chemical environment around each nanotube, controlling how airborne molecules approach and adhere to the surface. Even weakly interacting compounds, including plant-derived terpenes, produce measurable electronic changes when they bind to these modified nanotubes. The team reported that the sensor could detect the (−)-limonene form at concentrations as low as 1.5 parts per million, which is significantly more sensitive than many existing methods.
To understand why the system works, the researchers combined electrical measurements with computational modeling. The simulations showed that each enantiomer interacts with the sugar-coated nanotube in a slightly different way. These small variations influence the flow of electrons through the nanotube, generating distinct electrical signatures that allow the sensor to separate one mirror image from the other. By testing multiple sugar-based receptor designs, the team identified which structural features most strongly affected selectivity, offering a guide for future sensor development.
This work is part of the broader SMELLODI consortium, which studies how chemical signals relate to physiological and emotional states. Many applications — including breath diagnostics, environmental monitoring and quality control in food and fragrance production — rely on accurate detection of complex mixtures of volatile organic compounds. The ability to discriminate between nearly identical molecules could improve the sensitivity and usefulness of electronic nose technologies.
The approach is also notable from an engineering standpoint. Sugars typically dissolve in water and are not obvious candidates for stable gas-phase sensing materials. To overcome this, the team created a modular two-part receptor system: a sugar-based scaffold providing molecular recognition, supported by carbon nanotubes that convert binding events into electrical signals. The design can be adjusted to target different classes of molecules by altering the sugar structure or the attached chemical groups.
Looking ahead, the researchers suggest that computational tools, including machine-learning-guided molecular design, could expand the range of detectable compounds and enhance the precision of enantiomer recognition. As electronic sensing technologies evolve, customizable receptor architectures like this one may play a central role in building reliable, application-specific gas-sensing systems for medicine, environmental analysis and manufacturing.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
