Zhang, K. / Jian, Y. / Heinke, L. (2023)

Chem. Commun., 2023,59, 8704-8707

Abstract

An optical sensor array based on photonic Fabry–Pérot films of surface-mounted metal–organic-frameworks (SURMOFs) with different homochiral structures is presented. It is used to detect and enantioselectively discriminant 3 pairs of chiral odor molecules, either pure or in binary mixtures. Chirality and enantioselectivity are fundamental in nature and chiral messenger molecules are often the key to biological information transmission. Most chiral odor molecules have an enantioselective smell, which can be typically discriminated by the human olfactory system. One of the most popular examples is limonene: While the R-isomer of limonene (R-Lim) has an odor of an orange, the S-isomer (S-Lim) smells like lemons. Another example is 1-phenylethanol: the R-isomer (R-PhOH) has a floral, earthy-green odor, while the odor of the S-isomer (S-PhOH) is described like a mild hyacinth with strawberry nuances. For accurate discrimination, the chiral odors are mostly detected through enantioselective chromatography with homochiral columns. However, due to its complexity, time-consumption and costs, it is not suited for practical sensor applications. Several efforts have been made to fabricate portable enantioselective sensors based on different chiral materials such as chiral polymers, supramolecular chiral systems, cyclodextrin, carbon-nanotubes, or graphene functionalized with chiral molecules. For example, DNA-functionalized carbon nanotubes have been used for the distinction of R- and S-enantiomers of α-pinene as well as of β-pinene and limonene (separately).

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