Skip to main content
. Author manuscript; available in PMC: 2023 Feb 21.
Published in final edited form as: Angew Chem Int Ed Engl. 2022 Jan 14;61(9):e202112995. doi: 10.1002/anie.202112995

Figure 1.

Figure 1.

The surveillance approach uses a color change based on peptide-gold assembly. (a) Schematic illustration of the aggregation of bis(p-sulfonatophenyl)phenylphosphine-coated gold nanoparticles (BSPP-AuNPs) caused by the proteolytic hydrolysis of the intact peptide where the net charge of intact peptide and its fragment is reversed. The green cartoon designates proteases, i.e., Mpro; the tandem hexagon represents a modular zwitterionic peptide with a Mpro recognition site. (b) The colorimetric test could be coupled with face coverings with a lateral flow strip to indicate COVID infection in-situ (top). White-light image of BSPP-AuNPs after incubating with the proteolytic products. The visual color shifts from ruby red to violet-blue with increasing amount of Mpro from 0−200 nM (bottom). (c) TEM images of the dispersed BSPP-AuNPs (top) and proteolysis-induced gold aggregates [bottom, (i)]. The flocculated AuNPs can be redispersed using ionic surfactant additives, such as sodium dodecyl sulfate [SDS, (ii)], due to the restored electrostatic repulsion.