Researchers, published in ACS Nano, have developed a prototype device that non-invasively detects COVID-19 in the exhaled breath. Currently, COVID-19 testing requires RT-PCR, a time-consuming laboratory procedure. Due to the massive volume of testing at the moment, backlogs can often occur, causing a delay in results. In order to enact the most effective health care outcome, healthcare systems need quick, inexpensive and easy-to-use tests.
Hossam Haick, Hu Liu, Yueyin Pan and colleagues wanted to develop a nanomaterial-based sensor that could identify COVID-19 in exhaled breath. Their concept is akin to a breathalyzer test for alcohol intoxication. Previous studies have demonstrated a proof of concept in that the viruses and the cells they infect emit volatile organic compounds (VOCs) that can be exhaled in the breath.
The researchers utilized gold nanoparticles linked to molecules that are sensitive to various VOCs. When VOCs interact with the molecules on a nanoparticle, the electrical resistance changes. The researchers designed the sensor to detect COVID-19 using machine learning to compare the pattern of electrical resistance signals obtained from the breath of 49 confirmed COVID-19 patients with those from 58 healthy controls and 33 non-COVID lung infection patients in Wuhan, China.
Study participants exhaled into a device for 2-3 seconds. Once machine learning identified a potential COVID-19 signature, the team tested the accuracy of the device on a subset of participants. In the test set, the device demonstrated 76% accuracy in detecting COVID-19 cases from controls and 95% accuracy in discriminating COVID-19 cases from lung infections. The sensor could also distinguish, with 88% accuracy, between sick and recovered COVID-19 patients.