A Handheld Microchip for GC Analysis of Breath to Screen for COVID-19

The COVID-19 pandemic has caused unprecedented societal suffering and economic disruption. Although current COVID-19 diagnostic testing technologies are critical for curbing the spread of the virus and preventing future outbreaks, they are not practical for field use. Current diagnostic tests are cumbersome to perform because they use aqueous solutions, require multiple steps, and hours-to-days to obtain results. Therefore, there is an urgent need to develop a diagnostic approach that is non-invasive, portable, and can rapidly provide test results. The overall goal of the project was to develop a mobile breath analysis technology for rapid screening for COVID-19 using a handheld breath collection tool and a portable GC with a photoionization detector (PID). The handheld tool was a closed system for trapping target volatile organic compounds (VOCs) on a microfabricated chip. The captured VOCs were eluted with a solvent and then analyzed using a portable GC-PID instrument. Artificial intelligence (AI) and machine learning algorithms were applied to recognize the VOC pattern that correlates with COVID-19 infection. The central innovation was the microfabricated chip that captured VOCs in exhaled breath and thus served as a preconcentrator, which enabled analysis of the captured VOCs by the portable GC-PID. The hypothesis was that VOC metabolome in exhaled breath was directly related to the body's reaction to tSARS-CoV-2 infection, and the changes of VOC profile in exhaled breath relative to healthy controls were used to detect both symptomatic and asymptomatic COVID-19 patients. The University of Louisville was uniquely suited to rapidly transition the microchip technology to field use because of the PI and Co-PI's experience in breath analysis and translational research, and the project team's experience in virology, infectious diseases, biostatistics, and artificial intelligence as well as the state-of-the-art facilities that include a MicroNano Technology Center, Biosafety Level 3 Regional Biocontainment Lab, and an NIH-funded REACH program.