title: Colorimetric detection of influenza A virus using antibody-functionalized gold nanoparticles.
abstract: Early and accurate diagnosis is considered the key issue to prevent the further spread of viruses and facilitate influenza therapy. Herein, we report a colorimetric immunosensor for influenza A virus (IAV) based on gold nanoparticles (AuNPs) modified with monoclonal anti-hemagglutinin antibody (mAb). The immunosensor allows for a fast, simple, and selective detection of IAV. In this assay, influenza-specific antibodies are conjugated to AuNPs to create mAb-AuNP probes. Since IAV has multiple recognition sites for probes on the surface, the mAb-AuNP probes can be specifically arranged on the virus surface due to their very specific antigen recognition. In this case, this aggregation of the mAb-AuNP probes produces a red shift in the absorption spectrum due to plasmon coupling between adjacent AuNPs, and it can be detected with the naked eye as a color change from red to purple and quantified with the absorption spectral measurements. The aggregate formation is also confirmed with transmission electron microscopy (TEM) imaging and dynamic light scattering (DLS). Under the optimal conditions, the present immunoassay can sensitively measure H3N2 IAV (A/Brisbane/10/2007) with a detection limit of 7.8 hemagglutination units (HAU). This proposed immunosensor revealed high specificity, accuracy, and good stability. Notably, it is a single-step detection using AuNP probes and UV-vis spectrophotometer for readout, and no additional amplification, e.g., enzymatic, is needed to read the result. This assay depends on an ordered AuNP structure covering the virus surface and can be applied to any virus pathogen by incorporating the appropriate pathogen-specific antibody.
authors.affiliation: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Jiangning District, Nanjing, 211189, PR China. weiw@seu.edu.cn.
authors.forename: Yuanjian
authors.initials: Y
authors.lastname: Liu
authors.forename: Linqun
authors.initials: L
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhao
authors.forename: Zhenxian
authors.initials: Z
authors.lastname: Zhou
authors.forename: Yuanjian
authors.initials: Y
authors.lastname: Zhang
authors.forename: Songqin
authors.initials: S
authors.lastname: Liu
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D007118:Immunoassay / Q000379:methods*; D053122:Influenza A Virus, H3N2 Subtype / Q000302:isolation & purification*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D000911:Antibodies, Monoclonal; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006046:Gold