A rapid, portable, and cost-effective method to detect the infection of SARS-CoV-2 is fundamental toward mitigating the current COVID-19 pandemic. Herein, a human angiotensin-converting enzyme 2 protein (ACE2) functionalized silver nanotriangle (AgNT) array localized surface plasmon resonance (LSPR) sensor is developed for rapid coronavirus detection, which 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 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 buffer and untreated saliva are determined to be 0.83 pM, 391 PFU/mL, and 625 PFU/mL, respectively, while the detection time is found to be less than 20 min. Thus, the AgNT array optical sensor could serve as a potential rapid point-of-care COVID-19 diagnostic platform. Localized surface plasmon resonance (LSPR) virus sensor was developed based on human angiotensin-converting enzyme 2 protein (ACE2) functionalized silver nanotriangle (AgNT) arrays. The sensor has high sensitivity and specificity to the receptor binding domain (RBD) of SARS-CoV-2 as well as human coronavirus NL63. Display omitted •ACE2 functionalized LSPR virus sensor has high sensitivity and specificity.•The limit of detection for human coronavirus NL63 is 625 PFU/mL in untreated saliva.•The detection time for coronavirus is determined to be less than 20 min.•This simple LSPR sensor can be performed using a handheld UV-Vis spectrometer.•Coronavirus detection model of LSPR sensor has been established.