title: A regenerating ultrasensitive electrochemical impedance immunosensor for the detection of adenovirus.
abstract: We report on the development of a regenerable sensitive immunosensor based on electrochemical impedance spectroscopy for the detection of type 5 adenovirus. The multi-layered immunosensor fabrication involved successive modification steps on gold electrodes: (i) modification with self-assembled layer of 1,6-hexanedithiol to which gold nanoparticles were attached via the distal thiol groups, (ii) formation of self-assembled monolayer of 11-mercaptoundecanoic acid onto the gold nanoparticles, (iii) covalent immobilization of monoclonal anti-adenovirus 5 antibody, with EDC/NHS coupling reaction on the nanoparticles, completing the immunosensor. The immunosensor displayed a very good detection limit of 30 virus particles/ml and a wide linear dynamic range of 10(5). An electrochemical reductive desorption technique was employed to completely desorb the components of the immunosensor surface, then re-assemble the sensing layer and reuse the sensor. On a single electrode, the multi-layered immunosensor could be assembled and disassembled at least 30 times with 87% of the original signal intact. The changes of electrode behavior after each assembly and desorption processes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy techniques.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2.
authors.forename: Donghai
authors.initials: D
authors.lastname: Lin
authors.affiliation: Defence Research & Development Canada - Suffield Research Centre, Medicine Hat, AB, Canada T1A 8K6.
authors.forename: Thompson
authors.initials: T
authors.lastname: Tang
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2; National Institute for Nanotechnology, National Research Council Canada, Edmonton, AB, Canada T6G 2M9.
authors.forename: D
authors.initials: D
authors.lastname: Jed Harrison
authors.affiliation: Defence Research & Development Canada - Suffield Research Centre, Medicine Hat, AB, Canada T1A 8K6.
authors.forename: William E
authors.initials: WE
authors.lastname: Lee
authors.affiliation: National Institute for Nanotechnology, National Research Council Canada, Edmonton, AB, Canada T6G 2M9. Electronic address: Abebaw.jemere@nrc-cnrc.GC.CA.
authors.forename: Abebaw B
authors.initials: AB
authors.lastname: Jemere
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000302:isolation & purification*; D000257:Adenoviridae Infections / Q000821:virology*; D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry
chemical_list: D006046:Gold
keywords: Adenovirus; Electrochemical impedance spectroscopy; Electrode regeneration; Gold nanoparticles modified electrodes; Self-assembly