Back to Search
Start Over
Fabrication of Anionic Sulfate-Functionalized Nanoparticles as an Immunosensor by Protein Immobilization
- Source :
- Langmuir. 26:7355-7364
- Publication Year :
- 2010
- Publisher :
- American Chemical Society (ACS), 2010.
-
Abstract
- Anionic sulfate (SO(4)(-))-functionalized polystyrene (PS) nanoparticles were prepared by the thermal decomposition of potassium persulfate (KPS) in the presence of sodium tetraborate via emulsion polymerization. The presence of a SO(4)(-) group at a solid/liquid interface of a particle surface was confirmed by a zeta potential value of -40.6 mV as well as the shifting of S 2p spectra toward a lower-binding-energy region around 162.7 eV (2p(3/2)) and 164.4 eV (2p(1/2)) in X-ray photoelectron spectroscopy (XPS) analysis. The electrostatic attraction between positively charged antibodies of human immunoglobulin G (hIgG) and cardiac troponin I (cTnI) and negatively charged particle surfaces was accomplished. The atomic force microscopy (AFM) measurement and bicinchoninic acid (BCA) assay results show binding structure between hIgG and antibodies of hIgG (anti-hIgG) with a gradual increase in particle diameter to 152.6 nm (bare), 170.2 nm (hIgG), and 178.9 nm (hIgG/anti-hIgG). Surface coverage densities of 331.4 ng/cm(2) (hIgG) and 320.3 ng/cm(2) (cTnI) and the binding capacity of hIgG to HyLite-750-labeled Fab-specific anti-hIgG (approximately 81.2%) indicate that the majority of hIgG was immobilized with a Y-shaped orientation. The sandwich immunoassay results provide the evidence that the immunological activity of cTnI on the PS nanoparticle surface was retained because the binding activity of the cTnI-PS nanoparticle/cTnI (antigen)/detection cTnI-antibody reaction showed a 5-fold higher activity than that of the cTnI-PS nanoparticle/human serum albumin (HSA)/detection cTnI antibody used as a negative control.
- Subjects :
- Anions
Surface Properties
Analytical chemistry
Emulsion polymerization
Nanoparticle
Antibodies
Antigen-Antibody Reactions
chemistry.chemical_compound
X-ray photoelectron spectroscopy
Electrochemistry
Zeta potential
Humans
Bicinchoninic acid assay
General Materials Science
Particle Size
Spectroscopy
Immunoassay
Sulfates
Troponin I
Models, Immunological
Surfaces and Interfaces
Potassium persulfate
Condensed Matter Physics
chemistry
Immunoglobulin G
Nanoparticles
Polystyrenes
Particle
Polystyrene
Nuclear chemistry
Subjects
Details
- ISSN :
- 15205827 and 07437463
- Volume :
- 26
- Database :
- OpenAIRE
- Journal :
- Langmuir
- Accession number :
- edsair.doi.dedup.....586e0b7cf1118ba8c6588721bb49c5d8