title: Piezoelectric immunosensor for bisphenol A based on signal enhancing step with 2-methacrolyloxyethyl phosphorylcholine polymeric nanoparticle.
abstract: An immunoassay in which BPA competed with a BPA-horseradish peroxidase conjugate for binding to anti-BPA antibodies, coupled to a piezoelectric (PZ) immunosensor, was able to detect 0.1 ng mL(-1) BPA. To enhance the sensitivity of the assay, we tested nanoparticles approximately 200 nm in diameter, coupled to anti-BPA antibodies, to increase the mass change on the surface of the immunosensor and thereby increase the frequency shift detected. This second step, using nanoparticles coated with anti-BPA antibodies, improved the sensitivity of the assay by approximately eight times at BPA concentrations below 10 ng mL(-1). Field emission-scanning electron microscopy (FE-SEM) showed that polymeric 2-methacrolyloxyethyl phosphorylcholine (MPC) nanoparticles coupled to antibodies remained monodisperse on the surface of the immunosensor and therefore produced stable signals in the immunosensors. Since the frequency shift detected in the assay mainly originated from the mass change on the surface of the PZ crystal, the colloidal stability of the antibody-conjugated particles used in the enhancement step played an extremely important role in achieving a stable and highly sensitive signal.
authors.affiliation: Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 1-1Higashi, Tsukuba 305-8565, Japan.
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Park
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kurosawa
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Aizawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Goda
authors.forename: Madoka
authors.initials: M
authors.lastname: Takai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ishihara
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D001559:Benzhydryl Compounds; D001667:Binding, Competitive; D015374:Biosensing Techniques / Q000379:methods; D007118:Immunoassay / Q000379:methods; D008689:Methacrylates; D049329:Nanostructures; D010636:Phenols / Q000032:analysis* / Q000276:immunology; D010767:Phosphorylcholine / Q000031:analogs & derivatives; D000098826:Bisphenol A Compounds
chemical_list: D000911:Antibodies, Monoclonal; D001559:Benzhydryl Compounds; D008689:Methacrylates; D010636:Phenols; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine; C006780:bisphenol A; D000098826:Bisphenol A Compounds