Chiral behavior of TGS gas sensors: Discrimination of the enantiomers by the electronic nose

The electronic nose measurement system composed of TGS a gas sensor array, cooperating with the support vector machine (SVM) to discriminate between enantiomeric odor pairs: (+) and (−) of α-pinene, carvone and limonene forms is proposed in the paper. The array of the semiconductor TGS gas sensors of an electronic nose responds with a signal pattern characteristic of each enantiomer type. The SVM classifier is responsible for the recognition of this pattern. This study demonstrates that the ability of recognition of these enantiomers can be explained as the chiral behavior of the TGS gas sensors. Chirality of these sensors can be joined with the chirally selective adsorption on the metal oxide crystal surfaces. The ability of some inorganic crystalline surfaces to adsorb selectively chiral molecules is widely spread in the nature.