Fig. 1.

A conventional LFA structure (A). Adapted by permission from Ref. [88]. A design concept for LFA, and the synthesis procedure of Au NPs (B). Adapted by permission form Ref. [45]. The Au NPs LF strip's operating principle and specificity of AuNP-LF strips for SARCS-CoV-2 (C). Adapted by permission from Ref. [46] Structure of a LNP-based LFA applied for SARCS-CoV-2 detection (D). Adapted by permission from Ref. [79]. Schematic depiction of a LFA with Au NPs coated by spike protein from SARS-CoV-2 on the wicking membrane (E). Adapted by permission from Ref. [85].