Abstract: Methods and systems of the invention can determine the identity and quantity of analytes in a vapor. In preferred methods, a porous optical film is exposed to vapor which contains analyte. The porous optical film is heated and its optical response is monitored during heating. An optical response observed via heating can determine the identity and/or quantity of the analyte. In preferred embodiments, optical response during a thermal pulse is compared to a database of sensor responses that are characteristic of various analytes. Preferred methods are conducted a relatively low temperatures, for example below about 200° C. In preferred methods, a heating and cooling cycle produces a hysteresis curve in the optical response that is indicative of analytes. In preferred embodiments, a thermal reset pulse resets the porous optical film for later use and also provides an optical response that can be used for sensing.

Abstract: An embodiment of the invention is a remote sensor that has an optical fiber terminating in a tip. A thin film porous particle having a characteristic optical response that changes in the presence of an analyte is optically coupled and physically attached to the tip of the optical fiber. The optical response of the particle changes in the presence of analyte, and the particle also serves to concentrate analyte. The thin film porous particle can be functionalized toward sensitivity for a predetermined analyte or analytes. A method of remote sensing exposes the remote sensor to an environment to be monitored for analyte. The thin film porous particle is probed with a beam of light. Reflected light is monitored through the optical fiber for a shift in frequency or intensity.