▎ 摘　　要

Humidity sensors with ultrafast response and recovery speed are highly desired in applications of dynamic situations, such as medical monitoring and industrial detection. A freestanding film for humidity sensing with ultrafast response is easily fabricated by supramolecular polymerization of graphene oxide and aniline (GOA). Its response/recovery time is as short as about 50 ms. The high-speed adsorption and desorption of water vapor on the surface of GOA benefit from the unique moderate hydrophobic surface caused by the hydrophilicity of the oxygen-containing functional group and the hydrophobicity of the benzene ring. Furthermore, the GOA sensor can work at high humidity and recover rapidly from full-water condition. Such ultrafast response and excellent water-durable property of GOA film facilitate the application for physiological or psychological monitoring by detecting humidity fluctuations of human body in real time.