Amplification‐Free Detection of SARS‐CoV‐2 Down to Single Virus Level by Portable Carbon Nanotube Biosensors

Abstract

AbstractThe rapid and sensitive detection of trace‐level viruses in a simple and reliable way is of great importance for epidemic prevention and control. Here, a multi‐functionalized floating gate carbon nanotube field effect transistor (FG‐CNT FET) based biosensor is reported for the single virus level detection of SARS‐CoV‐2 virus antigen and RNA rapidly with a portable sensing platform. The aptamers functionalized sensors can detect SARS‐CoV‐2 antigens from unprocessed nasopharyngeal swab samples within 1 min. Meanwhile, enhanced by a multi‐probe strategy, the FG‐CNT FET‐based biosensor can detect the long chain RNA directly without amplification down to single virus level within 1 min. The device, constructed with packaged sensor chips and a portable sensing terminal, can distinguish 10 COVID‐19 patients from 10 healthy individuals in clinical tests both by the RNAs and antigens by a combination detection strategy with an combined overall percent agreement (OPA) close to 100%. The results provide a general and simple method to enhance the sensitivity of FET‐based biochemical sensors for the detection of nucleic acid molecules and demonstrate that the CNT FG FET biosensor is a versatile and reliable integrated platform for ultrasensitive multibiomarker detection without amplification and has great potential for point‐of‐care (POC) clinical tests.