1. Context

Odorants contribute to aromas, can be a signature of metabolic or pathological states, emanate from drugs or explosives, and signal domestic and environmental pollutants. Consequently, there is growing interest in the emergence of technologies for the rapid, non-invasive assessment of volatile odorant compounds. Current e-nose devices based on metal oxide semiconductors or conductive polymers that specifically identify gaseous odorants are generally heavy and expensive, and therefore unsuitable for the development of micro- and nanosensors that could mimic the natural olfactory system. Furthermore, they do not involve the molecular identification of odorants, their operation is disrupted in the presence of water, and they require a substantial sample size to ensure optimal interaction with the sensor surface. It is therefore extremely tempting to develop new biosensors based on olfactory...