Volatile organic compounds (VOCs) are naturally released by plants and animals, emitted by human-made products, and odorize pollutants. VOC chirality differential between benign traits, such as a lemon or orange scent, but it can also determine hazardous from non-toxic substances.

However, many traditional detection methods require large, complex lab instruments and magnets to perform this detection. Maity and Haick review an alternative, magnet-free, and miniature method for discriminating chirality: taking advantage of preferred spin states in nanostructured materials.

A chiral compound cannot be superimposed on its mirror image, regardless of rotation or translation. As electrons interact with chiral structures, they favor certain spin states and induce spin-polarized currents.

Recently, scientists identified chiral volatile organic compounds using hybrid nanostructures of different dimensions. The authors discuss the chemical theory behind the new approach, its advantages compared to traditional methods using bulky magnetic instruments, and potential applications.

“Chiral and helical molecules’ ability to present a spin preference is utilized to detect specific spin states through carefully crafted nanostructures that offer coherence spin transport and the ability to distinguish opposite spin types or chiral vapors at the miniature scale,” author Hossam Haick said. “The interdisciplinary collaboration of experts from fields such as nanomaterials, spintronics, chemistry, and sensor engineering is essential for developing practical applications for the spin-controlled mechanism, thus contributing to the advancement of chiral sensing technologies and to the evaluation of its capacity to revolutionize chemical sensing, chiral gas phase spintronics, and drug research.”

Promising applications of spin-controlled chiral sensing include quantum computing, gas phase spintronics, spin-chemistry interactions, and real-time monitoring for hazardous chiral compounds in the food, pharmaceutical, and environmental industries.

Source: “Spin-induced nanomaterials for detection of chiral volatile organic compounds,” by Arnab Maity and Hossam Haick, Applied Physics Reviews (2023). The article can be accessed at https://doi.org/10.1063/5.0146656.

This paper is part of the Volatile Organic Compounds and their Applications Collection, learn more here.