Point/extractive sensors measure an analyte of interest at a given location by either placing the sensor at the location of interest or by conveying the analyte directly to the spectrometer for measurement. Various applications include health (e.g. breath analyzers) and environmental (e.g. greenhouse gas measurements) monitoring, with sensor transportability and robustness as key requirements for field deployability. An examples of a portable battery operated CO₂ sensor developed in our lab is shown above, demonstrating real-time, highly sensitive (ppm-level) unattended CO₂ measurements over days of deployment. Other sensors include a field-tested water-vapor isotope analyzer and transportable Faraday rotation spectrometer for NO monitoring in breath, blood and urine samples (deployed to Cleveland Clinic > 6 months for preliminary patient sample analyses). In addition to being highly-capable standalone sensors, these spectrometers may be coupled together to form sensor networks for spatial measurement of analytes (see below).

Projects:

• In-situ combustion diagnostics for HOx radical detection
• Faraday Rotation Spectroscopy for stable isotope tracer techniques
• Water Vapor Isotope Analyzer for Environmental Monitoring