Patent ID: 8741657

Claim:
A method of a detecting a change in a chemical composition of a gas stream comprising: generating the gas stream; placing a gas sensing material in the gas stream, where the gas sensing material is comprised of, an inert matrix, where the inert matrix is stable at the gas stream temperature, and where the inert matrix is optically transparent over a light wavelength range, and where the inert matrix has a bandgap greater than or equal to 5 eV and has an oxygen ion conductivity of less than 10 −7 S/cm at a temperature of 700° C., a plurality of gold nanoparticles dispersed in the inert matrix, where an individual gold nanoparticle in the plurality of gold nanoparticles is comprised of elemental gold, and where the plurality of gold nanoparticles have an average nanoparticle diameter of less than about 100 nanometers; contacting the gas sensing material with a monitored stream, where the monitored stream is at least a portion of the gas stream, and illuminating the gas sensing material with a light source emitting incident light; collecting exiting light, where the exiting light is light that originates at the light source and is transmitted or reflected by the gas sensing material, and monitoring a plasmon resonance peak based on a comparison of the incident light and the exiting light using absorption spectroscopy; and detecting a change in the plasmon resonance peak, thereby detecting the change in the chemical composition, and thereby monitoring the chemical composition of the gas stream.