Detection of environmental pollution, especially toxic gas, is important and critical to industry, agriculture, and public health. For example, NO_x gas is one of the most common air pollutants. It is a source of acid rain and can cause serious diseases. As such, there is an increasing demand to develop highly sensitive, low cost, and portable gas sensors with low power consumption.

Hua Zhang and co-workers, Nanyang Technological University, Singapore, have tested single- and multilayer MoS₂ films as part of field-effect transistors for sensing NO (pictured). The single-layer MoS₂ device showed a rapid response after exposure to NO, but the current was found to be unstable. The two-, three-, and four-layer MoS₂ devices showed both stable and sensitive responses to NO down to a concentration of 0.8 ppm.

^{Image: © Wiley-VCH}

• Fabrication of Single- and Multilayer MoS₂ Film-Based Field-Effect Transistors for Sensing NO at Room Temperature
  H. Li, Z. Yin, Q. He, H. Li, X. Huang, G. Lu, D. W. H. Fam, A. I. Y. Tok, Q. Zhang, H. Zhang,
  Small 2011.
  DOI: 10.1002/smll.201101016