Figure 1

Illustration of the principle of NanoDLSay used for serum protein detection and analysis. (A) Illustration of proteins in different forms. X refers to a target protein, while A, B, C, D, etc. refer to any known or unknown biomolecules that are complexed to the target protein X. (B) Different particle size increase caused by the adsorption or binding of proteins in different forms. (C) The principle of the assay used in the present study: In the first step of the assay, a serum sample is mixed with a citrate-protected AuNP solution. After the formation of a stable protein corona around the AuNPs, an antibody specific to the interested target protein is added to the assay solution. When a target protein is present on the nanoparticle surface, a further size increase of the nanoparticles can be observed through DLS measurement.