High Sensitive Gas Microsensors Based on Sulfonated Cnts and Cnts/polyaniline Mixture

A sensor is defined as a device which detects a variable quantity, usually a non-electric stimulus and converts it into electrical signals that are recorded. Measurement performances are defined by the sensitivity, selectivity, accuracy and stability characteristics of the sensor. Because of their high degree of selectivity and sensitivity, electrochemical sensors represent a very promising analytical method. Used in occupational safety, medical engineering, process measuring engineering, environmental analysis, food sector, they provide wide application fields of interest. Electrochemical sensors development based on nanomaterials, represent a signal amplification advantage and high detection resolution due to active layers superior conductivity, thermal stability and mechanical stress resistance. Two gas microsensors, based on SWCNT, were obtained and used for different gases detection, like CO, NH3, CO2. On an interdigitized gold electrode structure were deposited, as active layers, sulfonated carbon nanotubes (s-CNTs) and carbon nanotubes (CNTs)/Polyaniline (PANi) mixture, respectively. The obtained microsensors, characterized by high electrochemical activity and improved stability, could be a solution for an efficient low-powered sensor-system with practical application in the field of environmental monitoring, healthcare, automation, industrial process control, etc.