Fig. 1.

SARS-CoV-2 bioreceptors used in diagnostic devices: a schematic presentation of the SARS-CoV-2 viral particle organization presenting S (spike protein), E (envelope protein), M (membrane protein), and N (nucleocapsid protein); b schematic illustration of a spike protein together with its 3D structure; c single-stranded DNA approach as a surface ligand: genome positions according to GenBank, SARS-CoV-2 NC_045512 together with thiol-cDNA used (reprinted from ref. [11]); d antigen sensing approach based on IgG recognizing the RBD of the virus [14]; e structure of a proposed SARS-CoV-2 aptamer (together with the SARS-CoV-2 S1-protein complex) [17]