hi, guys
what is carbon nanotube? and

why is carbon nanotube for gas sensor?

Hi

A carbon nanotube is a cylindrical macromolecular structure of the element carbon. It can be visualised as a 2-dimensional sheet of carbon atoms connected in a hexagonal array (like one sheet of carbon atoms removed from the standard graphite structure), which has been rolled up so that the atoms at the edges of the sheet on two sides join up to form a 'tube'. The ends are often closed by hemispherical cages of carbon atoms. They are used for gas sensors because of their improved mechanical properties as well as large surface area and narrow tip width, which makes for a very robust and sensitive sensor.