title: Multiple label-free detection of antigen-antibody reaction using localized surface plasmon resonance-based core-shell structured nanoparticle layer nanochip.
abstract: In this research, a localized surface plasmon resonance (LSPR)-based bioanalysis method for developing multiarray optical nanochip suitable for screening bimolecular interactions is described. LSPR-based label-free monitoring enables to solve the problems of conventional methods that require large sample volumes and time-consuming labeling procedures. We developed a multiarray LSPR-based nanochip for the label-free detection of proteins. The multiarray format was constructed by a core-shell-structured nanoparticle layer, which provided 300 nanospots on the sensing surface. Antibodies were immobilized onto the nanospots using their interaction with Protein A. The concentrations of antigens were determined from the peak absorption intensity of the LSPR spectra. We demonstrated the capability of the array measurement using immunoglobulins (IgA, IgD, IgG, IgM), C-reactive protein, and fibrinogen. The detection limit of our label-free method was 100 pg/mL. Our nanochip is readily transferable to monitor the interactions of other biomolecules, such as whole cells or receptors, with a massively parallel detection capability in a highly miniaturized package. We anticipate that the direct label-free optical immunoassay of proteins reported here will revolutionize clinical diagnosis and accelerate the development of hand-held and user-friendly point-of-care devices.
authors.affiliation: Department of Mechano-Micro Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama, 226-8502, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Endo
authors.forename: Kagan
authors.initials: K
authors.lastname: Kerman
authors.forename: Naoki
authors.initials: N
authors.lastname: Nagatani
authors.forename: Ha Minh
authors.initials: HM
authors.lastname: Hiepa
authors.forename: Do-Kyun
authors.initials: DK
authors.lastname: Kim
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yonezawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakano
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tamiya
mesh_terms: D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000032:analysis*; D002097:C-Reactive Protein / Q000737:chemistry; D005340:Fibrinogen / Q000737:chemistry; D007136:Immunoglobulins / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D040901:Proteomics / Q000295:instrumentation / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D000941:Antigens; D007136:Immunoglobulins; D005340:Fibrinogen; D002097:C-Reactive Protein