Paper-based gas sensors: A cutting-edge exploration from functional materials to intelligent sensing

Abstract Paper-based gas sensors break through traditional detection barriers with lightweight, low-cost and environmentally friendly features, giving "paper" wisdom for accurate trace gas monitoring. Herein, the latest advances and primary challenges encountered in the design and manufacturing processes of paper-based gas sensors are elucidated. Initially, the working principles of chemiresistor, field effect transistor and electrochemical sensor are introduced in detail. Then, the selection and modification of paper matrix, the types of sensing materials and their effects on the performance of the sensor are deeply discussed. Moreover, notable progress related to the application of paper-based gas sensors in environmental monitoring, food safety, biomedicine and healthcare, and emergency management is described. In the end, the technical challenges and future directions of paper-based gas sensors are proposed. Based on these observations, the paper emphasizes the importance of combining the Internet of Things and artificial intelligence technology to realize the intelligent paper-based gas sensor, and predicts its wide application prospects in many fields. • The detailed working mechanisms for chemiresistor, field effect transistor, and electrochemical gas sensor are provided. • The selection of paper substrates along with the impact of sensing materials on sensor performance are discussed. • Advances in the application of paper-based gas sensors are described. • Technical challenges and future directions for intelligent paper-based gas sensors are identified.