Novel nanoelectronic systems for gas sensing and separation applicable to breath analysis and medical diagnosis
Department of Biomedical Engineering
University of Michigan, Ann Arbor
Host: Xu Yi
Time and Location: Friday, October 16, 2020 2:00pm
Abstract: Volatile organic compounds (VOCs) in exhaled breath carry invaluable information on the physiological and metabolic status of the human body, which emerges as potential means for non-invasive clinical diagnosis and therapeutic monitoring. Rapid and accurate VOC analysis for point-of-care applications relies on the development of sophisticated analysis method and instrumentation, including miniaturized gas chromatography (GC) system for targeted compound identification and vapor sensors for sensitive and fast vapor detection and quantification.
In this talk, I will first introduce a novel nanoelectronic vapor sensing technique by exploiting the incomplete screening effect due to the semi-metallic nature of graphene. Rapid (sub-sec) and sensitive (sub-ppb) detection of both polar and non-polar analytes is achieved. Electrical probing and tuning of molecular physisorption on graphene were demonstrated by using the as-developed sensor as testbed. Next, leveraging graphene’s gate tuning effect, we developed an ultra-compact GC system with monolayer graphene as the stationary phase. Fast, efficient, and electrically tunable vapor molecules separation is achieved with extremely low power consumption. Last, I will introduce a fully automated portable two-dimensional GC system for on-site monitoring of patients’ breath at the University of Michigan Hospital. Breath chromatograms of patients were characterized by our system and analyzed using machine learning, which enables the biomarker identification for diagnosing multiple diseases, including asthma, lupus, acute respiratory distress syndrome (ARDS), and COVID-19.
Biography: Dr. Wenzhe Zang is currently a postdoctoral fellow in the Department of Biomedical Engineering at University of Michigan, Ann Arbor under the supervision of Prof. Xudong Fan. She received her B.Sc. degree in Chemistry from Nanjing University in China, and Ph.D. degree in Electrical Engineering from University of Michigan, Ann Arbor in 2020. Her research interests focus on nanoelectronic chemical sensing, novel gas chromatography system, and tailored electronic devices for biomedical applications.