Rapid and high-sensitive LSPR sensor for coronavirus detection

A rapid, portable, and cost-effective method to detect the infection of SARS-CoV-2 is fundamental toward mitigating the current COVID-19 pandemic. A localized surface plasmon resonance (LSPR) sensor based on human angiotensin-converting enzyme 2 protein (ACE2) functionalized silver nanotriangle array is developed for rapid coronavirus detection. The sensor is validated by SARS-CoV-2 spike RBD protein and CoV NL63 virus with high sensitivity and specificity. A linear shift of the LSPR wavelength and transmission intensity at a fixed wavelength (750 nm) versus the logarithm of the concentration of the spike RBD protein and CoV NL63 is observed. The limits of detection for the spike RBD protein, CoV NL63 in untreated saliva are determined to be 0.38 pM, and 625 PFU/mL, respectively, while the detection time is found to be less than 20 min. Such a LSPR sensor could serve as a potential rapid point-of-care diagnostic platform for COVID-19.