A device for detecting airborne contaminants includes a protonated, electrically conductive sensing material with affinity for binding with, and capable of being deprotonated by, the airborne contaminant. Electronics measure a property of the sensing material that is sensitive to deprotonation and generates signals indicative of the airborne contaminant. A method for detecting airborne contaminants includes: determining a property change of the protonated, electrically conductive material; and determining presence of the airborne contaminant based on the change. A system for detecting airborne contaminants includes: a data center in remote communication with multiple sensing devices each having: protonated, electrically conductive sensing material with affinity for binding with, and capable of being depronated by, an airborne contaminant, and electronics for relaying signals indicative of a sensing material deprotonation property to the data center; and wherein a user associated with a sensing device is notified of an abnormal level of the airborne contaminant.