Biotechnology for e-noses: types and biomaterials

The ability to recognize millions of odors is a distinguishing feature of human and animal smell organs. It is accompanied by specific odor sensations, which serve as a basic source of information about the odor mixture. The olfactory receptors (ORs) are the primary structural elements of biological smell systems. Each of the ORs is coded with a separate gene and generally correlates to a different type of odor. Small differences in the structure of odorous molecules (odorants) can result in changes in the odor. In recent times, several researchers have attempted to improve artificial olfactory systems. Using ORs as sensing elements in a bioelectronic nose, molecular recognition could be improved. Cell-based, nanovesicle-based, DNA-based, and protein-based biosensors can be used in bioelectronic noses. The development of simple and rapid biosensors is necessary for their use as bioelectronic noses in various biomedical, environmental, anti-bioterrorism and food safety applications.