As early as Dec 2020, Torrente-Rodríguez et al. developed a multiplexed electrochemical graphene-based platform for the sensitive, rapid, and simultaneous detection of SARS-CoV-2 antigen, IgM and IgG antibodies and the inflammatory biomarker C-reactive protein (CRP), and this platform has been successfully used with saliva samples from COVID-19 patients [34]. Here, CRP is linked to COVID-19.