Effect of antibody immobilization strategies on the analytical performance of a surface plasmon resonance-based immunoassay

Analyst. 2011 Nov 7;136(21):4431-6. doi: 10.1039/c1an15325k. Epub 2011 Sep 8.

Abstract

Antibody immobilization strategies (random, covalent, orientated and combinations of each) were examined to determine their performance in a surface plasmon resonance-based immunoassay using human fetuin A (HFA) as the model antigen system. The random antibody immobilization strategy selected was based on passive adsorption of anti-HFA antibody on 3-aminopropyltriethoxysilane (APTES)-functionalized gold (Au) chips. The covalent strategy employed covalent crosslinking of anti-HFA antibody on APTES-functionalized chips using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC) and sulfo-N-hydroxysuccinimide (SNHS). The orientation strategy used passive adsorption of protein A (PrA) on Au chips, with subsequent binding of the anti-HFA antibody in an orientated fashion via its fragment crystallisable (Fc) region. In the covalent-orientated strategy, PrA was first bound covalently, to the surface, which in turn, then binds the anti-HFA antibody in an orientated manner. Finally, in the most widely used strategy, covalent binding of anti-HFA antibody to carboxymethyldextran (CM5-dextran) was employed. This immobilization strategy gave the highest anti-HFA antibody immobilization density, whereas the highest HFA response was obtained with the covalent-orientated immobilization strategy. Therefore, the covalent-orientated strategy was the best for SPR-based HFA immunoassay and can detect 0.6-20.0 ng/mL of HFA in less than 10 min.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Immobilized* / chemistry
  • Antibodies, Immobilized* / immunology
  • Antibodies, Immobilized* / metabolism
  • Dextrans / chemistry
  • Gold / chemistry
  • Gold / metabolism
  • Immunoassay / methods*
  • Propylamines
  • Silanes / chemistry
  • Staphylococcal Protein A / chemistry
  • Surface Plasmon Resonance / methods*
  • alpha-2-HS-Glycoprotein / analysis*
  • alpha-2-HS-Glycoprotein / immunology

Substances

  • Antibodies, Immobilized
  • Dextrans
  • Propylamines
  • Silanes
  • Staphylococcal Protein A
  • alpha-2-HS-Glycoprotein
  • Gold
  • carboxymethyl dextran
  • amino-propyl-triethoxysilane