title: Design of dual working electrodes for concentration process in metalloimmunoassay.
abstract: Electrochemical immunosensing, particularly through a metalloimmunoassay, is a promising approach for development of point-of-care (POC) diagnostics devices. This study investigated the structure of dual working electrodes (W1 and W2), used in a silver nanoparticles-labeled sandwich-type immunoassay and silver concentration process, paying special attention to the position of W1 relative to W2. The new structures of the dual working electrodes were fabricated for efficient silver concentration and evaluated experimentally, which showed that the duration of prereduction before current measurement decreased from 480 s to 300 s by transforming the position of W1 from 1 line to 2 lines or 6 parts. The experimental results were also compared with numerical simulations based on three-dimensional diffusion, and the prereduction step almost followed the three-dimensional diffusion equation. Using numerical simulations, the ideal structures of dual working electrodes were designed based on relationships between the structures and duration of prereduction or the LOD. In the case of 36 lines at an area ratio of W1 to W1 + W2 of 1 to 10, the prereduction duration decreased to 96 s. The dual working electrodes designed in this study promise to shorten the total analysis time and lower the LOD for POC diagnostics.
authors: Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan. n.hori@jaist.ac.jp.|School of Materials Science, Japan Advance Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan. n.hori@jaist.ac.jp.
authors: Nobuyasu
authors: N
authors: Hori
authors: School of Materials Science, Japan Advance Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
authors: Miyuki
authors: M
authors: Chikae
authors: Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271, Japan.
authors: Hiroya
authors: H
authors: Kirimura
authors: School of Materials Science, Japan Advance Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
authors: Yuzuru
authors: Y
authors: Takamura
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000737:chemistry / Q000276:immunology; D004553:Electric Conductivity; D004566:Electrodes; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry; D019095:Point-of-Care Systems; D012834:Silver / Q000737:chemistry*
chemical_list: D000914:Antibodies, Viral; D006514:Hepatitis B Surface Antigens; D012834:Silver
keywords: Concentration process; Dual working electrode; Electrochemical immunosensor; Metalloimmunoassay; Numerical simulation; Silver nanoparticle