▎ 摘　　要

This work demonstrates the use of graphene homogeneously bifunctionalized with NH2/NH3+ and dispersed in a hydrophilic matrix polymer as an active material to achieve an ultrafast breath sensor. This non-invasive sensor demonstrated a prompt response time to the breath (0.6 s) and high sensitivity (1900% Delta R/R), allowing monitoring the breathing behavior of an adult person, resolving 26 breaths/min. The high-performance is discussed and is related to the proton acceptor/donor ability from the functionalities NH2/NH3+. Furthermore, the methodology proposed here allows obtaining a fast, low-cost, and widely available breath sensor, increasing its promising application in the healthcare field for disease diagnostics such as sleep apnea, asthma, and cardiac arrest.