Applications of gold nanoparticles in virus detection

Draz, Mohamed Shehata; Shafiee, Hadi

With their characteristic red color, AuNPs have been exploited as colorimetric labels in a lateral-flow immunochromatographic assay (LFIA) to allow the immunological detection of HSV antigen. In this assay, the LFIA strip is preloaded with the labeling AuNP-anti-human IgG conjugates onto the conjugate pad, and the capturing IgG-1 and IgG-2 antigens, along with the anti-IgG antibody, are immobilized onto separate test and control lines directly next to the sampling area (Fig. 11A) . The sample is loaded and allowed to migrate across the strip with the chase buffer to react with the capturing antigens (IgG-1 and IgG-2) loaded on the test lines, as well as the anti-IgG antibody loaded on the control line. As a result, HSV antibodies are captured on the test lines and labeled with the loaded AuNP-DNA conjugates, causing characteristic red lines to appear. According to the color of the test lines, the samples can be qualitatively determined to be positive or negative within 20 min [59] .