Naked-Eye Sensitive Detection of Immunoglubulin G by Enlargement of Au Nanoparticles In Vitro This research was financed by grants from the National Natural Science Foundation of China (NSFC) and Tsinghua University.

Abstract

Growing gold: Human immunoglubulin G (h-IgG) can be detected by the naked eye after enlarging Au nanoparticles in vitro with HAuCl4/NH2OH⋅HCl, which immobilizes the Au nanoparticles on the nitrocellulose filter (see scheme; •=Au nanoparticle, ▪=anti-h-IgG, Y=h-IgG). The detection limit of approximately 10 pg mL−1 rivals the limits of fluorescent, radioactive, and enzyme-colorometric methods.