title: A single-step enzyme immunoassay capillary sensor composed of functional multilayer coatings for the diagnosis of marker proteins.
abstract: A single-step, easy-to-use enzyme immunoassay capillary sensor, composed of functional multilayer coatings, was developed in this study. The coatings were composed of substrate-immobilized hydrophobic coating, hydrogel coating, and soluble coating containing an enzyme-labeled antibody. The response mechanism involved a spontaneous immunoreaction triggered by capillary action-mediated introduction of a sample antigen solution and subsequent separation of unreacted enzyme-labeled antibodies and antigen-enzyme-labeled antibody complexes by the molecular sieving effect of the hydrogel. An enzyme reaction at the substrate-immobilized hydrophobic coating/hydrogel coating interface resulted in a protein-selective fluorescence response. An antigen concentration-dependent response was obtained for diagnostic marker protein samples (hemoglobin A1c (HbA1c), 7.14-16.7 mg mL(-1); alpha-fetoprotein (AFP), 1.4-140 ng mL(-1); C-reactive protein (CRP), 0.5-10 μg mL(-1)) that cover a clinically important concentration range. The successful measurement of CRP in diluted serum samples demonstrated the application of this capillary sensor.
authors.affiliation: Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai City, Osaka 599-8531, Japan. sueyoshi@chem.osakafu-u.ac.jp.
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Funano
authors.forename: Masato
authors.initials: M
authors.lastname: Sugahara
authors.forename: Terence G
authors.initials: TG
authors.lastname: Henares
authors.forename: Kenji
authors.initials: K
authors.lastname: Sueyoshi
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Endo
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hisamoto
mesh_terms: D000936:Antigen-Antibody Complex; D015415:Biomarkers / Q000032:analysis*; D002097:C-Reactive Protein / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D007124:Immunoenzyme Techniques / Q000379:methods*; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000936:Antigen-Antibody Complex; D015415:Biomarkers; D002097:C-Reactive Protein; D006442:Glycated Hemoglobin; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D000509:alpha-Fetoproteins; C517652:hemoglobin A1c protein, human