Quanta lost by electrons could be detected by proteins within the nose, say a group of physicists, and odor molecules could absorb these quanta and thereby be detected.   If their hypothesis is right, an "electronic nose" superior to any current chemical sensor could be created.

Luca Turin of MIT, speaking at the American Physical Society meeting, discussed how "vibrational modes" of odors could be their signatures.   Fies can distinguish between molecules that are chemically similar but in which a heavier version of hydrogen had been substituted, according to a recent study.

Quantum physics explanation for smell gains traction by Jason Palmer - BBC

A. P. Horsfield, Lianheng Tong, Yeong-Ah Soh, and P. A. Warburton, 'How to use a nanowire to measure vibrational frequencies: Device simulator results', J. Appl. Phys. 108, 014511 (2010); doi:10.1063/1.3459896