Paper Substrate-Based Polyaniline Hybrid Sensors for Efficient Room Temperature Ammonia Detection

Advanced material research has made wearable electronics one of the most active research areas, because their wearable applications offer real-time monitoring. Using the flexible substrate with compatible gas-sensing material in this paper, we report a flexible and room-temperature ammonia sensor based on a reduced graphene oxide - polyaniline (rGO-PANI) composite on a flexible paper substrate. This composite was made via an in situ chemical oxidative polymerization method. Filter paper was used as a flexible substrate where rGO was first drop-cast on the paper, and then, the rGO paper polymerization was done by soaking the paper in it. The polymerization time is optimized to determine the impact on gas sensing performance; at 100 ppm, the maximum response occurred after 6 h of polymerization (42%). To improve the performance of the sensor, we further incorporated an optimized rGO amount; due to the synergetic behavior of both rGO and PANI, the response increased (93% for 100 ppm) with a decrease in the response and recovery time (18/127 s) as compared to the bare PANI@paper. The proposed flexible sensor can be utilized for various applications ranging from healthcare monitoring to environmental and domestic use simply because of its easy fabrication process, inexpensive nature, and high sensing performance.