Comparative study of gas sensing microsensors based on sulfonated CNTs and CNTs/Polyaniline mixture

Two gas microsensors, based on SWCNT, were obtained and used for different gases detection, like CO, NH
₃
, CO
₂
. On an interdigitized gold electrode structure were deposited, as active layers, sulfonated carbon nanotubes (s-CNTs) and carbon nanotubes (CNTs)/Polyaniline (PANi) mixture, respectively. In order to obtain sulfonated CNT, the available CNTs were activated in a sulfuric acid solution, under different temperatures gradients ranging from 60°C to 300°C. With the obtained microsensors based on sulfonated CNTs, the response and recovery time where investigated and the results are presented and compared. In the case of carbon nanotubes (CNTs)/Polyaniline (PANi) mixture the electrical conductivity of PANi in the deposited layer could be orders of magnitude boosted by controlled doping of polyaniline level in the relative carbon concentration. The obtained microsensors presents improved electrochemical activity and stability in their structure. An efficient low-powered sensor-system based on the presented microsensors represent a viable solution for possible practical application in the field of environmental monitoring, automation, nuclear industry, industrial process control, etc.