A detector is provided including a plurality of nanofiber chemical sensors, each having an electrical characteristic; and a processing and alarm circuit in electrical communication with the plurality of nanofiber chemical sensors; wherein the electrical characteristics of at least one of the plurality of nanofiber chemical sensors changes in the presence of a first airborne material; wherein the electrical characteristics of at least one of the plurality of nanofiber chemical sensors changes in the presence of a second airborne material; and wherein the changes in the electrical characteristics of at least one of the plurality of nanofiber chemical sensors in the presence of the first airborne material are different from the changes in the electrical characteristics of at least one of the plurality of nanofiber chemical sensors in the presence of the second airborne material.