Single-Walled Carbon Nanotube Networked Field-Effect Transistors Functionalized with Thiolated Heme for NO₂ Sensing

The gas sensing properties of the single-walled carbon nanotube networked field-effect transistors for NO₂ are investigated. After the modification of the gold contact electrodes of the carbon nanotube transistors with the thiolated heme, the NO₂ sensing results indicate that the sensing sensitivity of the modified transistors is enhanced greatly and the sensing limit can reach below 100 ppb. It is also proposed that the mechanism of the sensitivity enhancement for NO₂ detection mainly results from the modulation of the Schottky energy barrier at the Au/CNTs junction upon thiolated heme facilitated NO₂ adsorption.