A wearable and highly sensitive CO sensor with a macroscopic polyaniline nanofiber membrane

A wearable CO sensor based on a macroscopic membrane which consists of polyaniline (PANI) coated electrospun nanofibers is reported. The membrane material has a centimeter range macro-film shape with highly porous networks and an ultra-fine nanofiber structure modified with PANI nanocones by an in situ polymerization route, making it a suitable candidate for sensing materials. Sensors based on the macro-PANI nanofiber membrane are constructed, displaying a rapid response (20 s) to CO with a high detection limit (2.5 ppb) at room temperature. Furthermore, by replacing the nanofiber template with natural cotton fibers, a sensing material towards wearable sensors is manufactured and excellent sensing responses are also detected. This work provides a simple process to make macroscale sensing materials with homogeneous, subtle nanoscale architecture and offers significant opportunities for wearable sensors.