title: Influenza virus immunosensor with an electro-active optical waveguide under potential modulation.
abstract: Here we report the development of a novel immunosensor-based strategy for label-free detection of viral pathogens by incorporating a sandwich bioassay onto a single-mode, electro-active, integrated optical waveguide (EA-IOW). Our strategy begins with the functionalization of the electro-active waveguide surface with a capture antibody aimed at a specific virus antigen. Once the target antigen is bound to the photonic interface, it promotes the binding of a secondary antibody that has been labeled with a methylene blue (MB) dye. The MB is a redox-active probe whose optical absorption can be electrically modulated and interrogated with high sensitivity by a propagating waveguide mode. In this effort, we have targeted the hemagglutinin (HA) protein from the H5N1 avian influenza A virus to demonstrate the capabilities of the EA-IOW device for detection and quantification of an important antigen. Our initial results for the HA H5N1 influenza virus show a remarkable limit of detection in the pico-molar range.
authors.forename: Jafar H
authors.initials: JH
authors.lastname: Ghithan
authors.forename: Monica
authors.initials: M
authors.lastname: Moreno
authors.forename: Guilherme
authors.initials: G
authors.lastname: Sombrio
authors.forename: Rajat
authors.initials: R
authors.lastname: Chauhan
authors.forename: Martin G
authors.initials: MG
authors.lastname: O'Toole
authors.forename: Sergio B
authors.initials: SB
authors.lastname: Mendes
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004560:Electricity; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000032:analysis; D007118:Immunoassay / Q000295:instrumentation*; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology* / Q000302:isolation & purification; D057230:Limit of Detection; D055096:Optical Devices
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus