Graphene-based gas sensor analysis for disease detection applications

This thesis presents an analysis of graphene sensors for the measurement of ultra-low concentrations of volatile organic compounds (VOCs) found in human breath. Adsorption of gas molecules to graphene sensing elements is measured as a function of various conditions, including gas concentration and flow. This analysis is foundational in enabling the use of such sensors for detection of biomarkers within the breath, which could ultimately lead to new, non-invasive detection of diseases such as lung cancer. A method of producing graphene samples for measurement will be discussed, using scalable and cost-effective nanomanufacturing methods. Finally, this thesis will describe the design and fabrication of a test system capable of supplying low parts-per-million (PPM) concentrations of VOC flow across the sensor. The testing system can flow multiple VOCs at a wide range of concentrations, and at sub-atmospheric pressures, to isolate the VOC of interest for highly accurate and sensitive measurements. Preliminary sensitivity data of graphene sensors to acetone will be reported. The test system can be used for future sensor testing of new designs, or sensitivity to different VOCs.Mechanical Engineerin