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.

Systematic review of the impact of point‐of‐care testing for influenza on the outcomes of patients with acute respiratory tract infection

“…In the past decade, numerous studies reporting the diverse use of nanoparticles in POCT have received great interest because of their unique chemical and physical properties . Several research groups have proposed simple colorimetric approaches based on controlled assembly of gold nanoparticles on the surface of viruses, including influenza . The limit of detection of these proposed methods is up to 385 times lower than that of conventional enzyme‐linked immunosorbent assay .…”

Cost-effective and sensitive colorimetric immunosensing using an iron oxide-to-Prussian blue nanoparticle conversion strategy

“…11 Among those colorimetric probes, noble metal nanomaterials, especially gold nanoparticles (NPs), have been extensively used in nanoparticle aggregation-based colorimetric assays due to their high extinction coefficients and distance-dependent optical properties. 12, 13 However, gold NPs as colorimetric probes have to be confronted with some limitations for their wide application especially in resource-limited settings because of their intrinsic high cost. In order to achieve satisfactory sensitivity, the usage of complex nanoparticle stabilizing ligands and multiple signal amplification processes are generally indispensable in these colorimetric assays.…”

Sensitive electrochemical assaying of DNA methyltransferase activity based on mimic-hybridization chain reaction amplified strategy

“…a Oligo name Sequence (5 0 e3 0 ) work [41] and their concentration was estimated to be~10 nM. Secondly, 1 mg BSPP was added in 1 mL AuNPs solution to open sulfhydryl bond.…”