I. Introduction
Nanosized materials have gained much interest for fabricating new conductor gas sensors due to their great surface activity. Silicon nanowires [1]–[3], single-wall carbon nanotubes (SWNTs) [4]–[8], and metal–oxide nanowires [9], [10] have been used to fabricate highly sensitive and selective sensors for detection of chemical and biological species. sensors are being actively studied [11], [12] and have many applications in the fields of space launch vehicles, industrial leak detection, and automobile fuel additives.