Flexible Screen-Printed CNT Electrode on Porous PTFE Substrate with Gold Nanoparticle Modification for Rapid Electrochemical Gas Sensing

摘要

Extensive attentions have been paid to gas sensors that play critical roles in gas sensing for various applications such as industrial manufacturing, environmental monitoring and human safety. Among all gas sensing approaches, electrochemical gas sensing reveals remarkable merits in high sensitivity, low detection limit, high selectivity and easy miniaturization. However, conventional electrochemical sensors suffer from two inherent drawbacks: short lifetime due to the evaporation of electrolyte and long response time due to the low diffusion rate of gas target in electrolyte. Different strategies have been proposed to solve the two issues such as new electrolyte and new sensor structure design. In our previous study, room temperature ionic liquid (RTIL) was utilized as the electrolyte in gas sensors featuring negligible vapor pressure, high thermal stability and wide potential window, thus implementing long lifetime of the sensor. To achieve short response time, porous polytetrafluoroethylene (PTFE) was used as the substrate for electrode patterning using microfabrication, and gases can directly diffuse through the substrate from the backside rather than the electrolyte from the front, which can achieve fast response. However, microfabrication requires expensive equipment and professional personnel and lacks sufficient flexibility. In this work, we proposed a new flexible screen-printed carbon nanotube electrode with gold nanoparticles modification to implement rapid and high sensitive gas sensing. Preliminary results were presented to validate the feasibility of the approach for gas sensor design and gas sensing.