A breath collection device can detect changes associated with pathogenesis of a disease, such as COVID-19, including biomarkers of immune response for respiratory symptoms, central nervous system injury, and/or peripheral nervous system injury in user breath and/or odor. The breath collection device can detect concentrations of alcohol, acetone, and carbon monoxide in user breath samples. A breath sample can be received in an internal bladder of the device for sensor analysis. Concentrations of alcohol, acetone, and carbon monoxide can be determined by calibrated calculation. A detection method for alcohol, acetone, and carbon monoxide can provide a non-invasive, rapid, and selective detection of gases in a variety of applications in virus detection as well as agricultural and homeland security.Medical Diagnostics
