Optimization of E-nose technology for detecting nonanal: a COVID-19 biomarker in exhaled breath

Abstract

International audienceA low-cost, rapid and non-invasive diagnosis of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection is needed for the prevention and control of the pandemic. Coronavirus disease 2019 (COVID-19) mainly affects the respiratory tract and lungs. Therefore, analysis of exhaled breath could be an alternative scalable method for reliable SARS-CoV-2 screening. In this work, an experimental protocol using an electronic nose (“e-nose”) for identifying a specific respiratory imprint in COVID-19 patients was optimized. The analytical performances of the Cyranose ® , a commercial e-nose device, were characterized by using a gas rig. In addition, the effect of various experimental conditions on its sensor array response was assessed, including relative humidity, sampling time and flow rate, aiming to select the optimal parameters. We also evaluated whether the Cyranose ® could distinguish between expired air from five healthy patients spiked or not with nonanal, identified as one putative COVID-19 biomarker. Electrical resistance variation of 32 sensors was recorded in real-time by using the PC-nose software during all tests. A statistical data analysis was applied to e-nose sensor response using a software called “Enair” developed on purpose and using a built-in optimized algorithm.Cyranose® reveals a possible detection of low concentrations of nonanal (5 ppb) in breath and a significant discrimination from others Volatile Organic Compounds (VOCs) of healthy patients