Fabrication and Optimization of Conductive Paper Based on Screen-Printed Polyaniline/Graphene Patterns for Nerve Agent Detection

In this work, a high-performance sensor capable of effectively detecting nerve gas, a type of chemical warfare agent, was realized by conductive paper with polyaniline (PANI) nanofiber and graphene sheet. To realize the high-performance nerve gas sensor, dimethyl methylphosphonate (DMMP) was used as a model of nerve gas, and the conductive paper sensor was used to detect DMMP at a concentration of parts per billion within a few seconds. Improvements in electrical properties and sensor performance of conductive papers were realized by the addition of optimized amounts of graphene (0.14 wt %) and polyethylene oxide (13.1 wt %). In addition, poly(vinylbutyral-co-vinyl alcohol-co-vinyl acetate) (P(VB-co-VA-co-VAc)) copolymer significantly improved the intermolecular forces between PANI nanofiber, graphene sheet, and cellulosic paper. Conductive patterns containing PANI nanofiber/graphene cofillers were fabricated into sensor electrodes of various sizes and shapes by screen printing. The prepared conductive papers were exposed under DMMP at various concentrations of at least 3 to at most 30 000 ppb. The conductive paper sensor containing PANI nanofiber/graphene cofillers exhibited a minimum detectable level of 3 ppb, a response time of 2 s, and a recovery time of 35 s, and the sensor realized a high life cycle. Furthermore, the conductive paper sensor demonstrated excellent selectivity to selectively detect DMMP from other harmful substances, such as methanol and chloroform. It is expected that the conductive paper sensor will be a very useful means to protect the safety of people when it is widely spread.