Concept of Bioelectronic Nose - Bioelectronic Nose: Integration of Biotechnology and Nanotechnology - page 1

Chapter 1
Concept of Bioelectronic Nose

Jong Hyun Lim and Tai Hyun Park

Abstract Sense of smell is an important sense to recognize environmental con-
ditions and dangerous situations. Following the identification of the olfactory
mechanism in the early 1990s, extensive studies to develop electronic devices that
mimic the function of animal noses have been conducted. Most devices have been
composed of an array of several sensors that react to chemical compounds. The
odor is characterized by analyzing the response patterns generated by the sensor
array. However, such devices have limitations in terms of sensitivity and selectiv-
ity. Hence, a novel concept for sensor devices functionalized with odor-recognizing
biomolecules was suggested. Sensors which use biomolecules as a primary sensing
material are commonly called bioelectronic noses. A bioelectronic nose generally
consists of primary and secondary transducers. The primary transducer is a biologi-
cal recognition element such as olfactory receptors and odorant-binding proteins.
The secondary transducer is a highly sensitive optical or electrical sensor platform
that converts biological events into measurable signals. In this chapter, the basic
concept and principles of bioelectronic noses are described. In addition, specific
characteristics of bioelectronic noses and the current issues are presented.

1.1 History of Artificial Smelling Methods

1.1.1 Trained Animal

Sense of smell is the most mysterious sense among five senses, and its biological
mechanism was revealed relatively later than with other senses. This sense has been
instinctually used for the perception of dangerous situations or subtle changes in
the environment. For instance, fire can easily be recognized through the smell of
smoke, and the spoilage of food can be determined by their putrid odors. However,
humans have insensitive noses. Non-human vertebrates such as dogs and mice have
more types and numbers of olfactory sensory neurons (OSNs) in their noses [ 1 - 3 ].