title: Facile fabrication of magnetic gold electrode for magnetic beads-based electrochemical immunoassay: application to the diagnosis of Japanese encephalitis virus.
abstract: A novel magnetic beads-based electrochemical immunoassay strategy has been developed for the detection of Japanese encephalitis virus (JEV). The magnetic gold electrode was fabricated to manipulate magnetic beads for the direct sensing applications. Gold-coated magnetic beads were employed as the platforms for the immobilization and immunoreaction process, and horseradish peroxidase was chosen as an enzymatic tracer. The proteins (e.g., antibodies or immunocomplexes) attached on the surface of magnetic beads were found to induce a significant decline in their electric conductivity. Multiwalled carbon nanotubes were introduced to improve sensitivity of the assay. The envelope (E) protein, a major immunogenic protein of JEV, was utilized to optimize the assay parameters. Under the optimal conditions, the linear response range of E protein was 0.84 to 11,200 ng/mL with a detection limit of 0.56 ng/mL. When applied for detection of JEV, the proposed method generated a linear response range between 2×10(3) and 5×10(5) PFU/mL. The detection limit for JEV was 2.0×10(3) PFU/mL, which was 2 orders of magnitude lower than that of immunochromatographic strip and similar to that obtained from RT-PCR. This method was also successfully applied to detect JEV in clinical specimens.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Mei
authors.forename: Yaoming
authors.initials: Y
authors.lastname: Li
authors.forename: Kaihong
authors.initials: K
authors.lastname: Zhao
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
authors.forename: Peng
authors.initials: P
authors.lastname: Wu
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Hu
authors.forename: Shengbo
authors.initials: S
authors.lastname: Cao
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D055664:Electrochemical Techniques; D004566:Electrodes; D004664:Encephalitis Virus, Japanese / Q000276:immunology / Q000302:isolation & purification*; D004672:Encephalitis, Japanese / Q000175:diagnosis* / Q000662:veterinary / Q000821:virology; D006046:Gold; D006735:Horseradish Peroxidase; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D008280:Magnetics; D014759:Viral Envelope Proteins / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D014759:Viral Envelope Proteins; D006046:Gold; D006735:Horseradish Peroxidase