Figure 11.

AuNP-based assays for herpes simplex virus (HSV), human cytomegalovirus (HCMV), and Kaposi's sarcoma-associated herpesvirus (KSHV). (A) Lateral-flow immunochromatographic assay of HSV-2 antibodies using AuNP anti-IgG probes. Sample addition followed by chase buffer addition causes gold nanoparticle (AuNP)-anti-IgG conjugates and the sample to migrate, contacting the test lines sequentially and resulting in the capture of type-specific antibodies to HSV-2. The concentration of HSV-2 antibody-AuNP complexes on the test line causes a corresponding pink color to form ⁵⁹. This scheme is similar to that reported for the detection of H5N1 ⁵⁸ and HIV-1 ⁹¹. (B) Electrochemical detection of HCMV by the acidic dissolution of AuNPs. HCMV DNA is directly labeled with specific AuNP-DNA probes. After the acidic dissolution of AuNPs, Au^III ions are measured by anodic stripping voltammetry (ASA) ⁶⁸. (C) Colorimetric one-pot NP-based assay of KSHV. This assay has been reported for the differential diagnosis of KSHV DNA and DNA from a frequently confounding Bartonella species. Upon the addition of sample DNA to a mixture of silver NP (AgNP)-DNA and AuNP-DNA conjugates specific for KSHV and Bartonella DNA, respectively, complementary DNA hybridization triggers the aggregation of bare NP conjugates and the subsequent decrease or disappearance of its corresponding color ⁶⁰.