Development of Sensor Substrate Materials for Spacecraft Air Quality Monitoring with SERS-Based Sensors

Studies are being performed to investigate the feasibility of surface enhanced Raman scattering (SERS) spectrometry for monitoring volatile organic compounds (VOCs) in air. The focus of these studies has been on the development and characterization of substrate materials that can be used for SERS measurements. The studies have shown that substrates can be fabricated that provide high SERS sensitivity and selectivity. Substrates include Au or Ag nanoparticles immobilized on silica or deposited on paper supports. Measurements of a model compound have shown that enhancements as high as 10¹⁰ to 10¹² can be achieved. Several VOC analytes have been investigated by SERS detection approaches, including indole, dimethyl sulfide, quinoline and benzoic acid. Studies have shown that substrates based on immobilized Au or Ag nanoparticles can be modified with surface coatings to enhance their SERS response.