Highly Efficient Binding of Paramagnetic Beads Bioconjugated with 100 000 or More Antibodies to Protein-Coated Surfaces
| Autor: | Challa V. Kumar, James F. Rusling, Dhanuka P. Wasalathanthri, Amit Joshi, Vigneshwaran Mani |
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| Rok vydání: | 2012 |
| Předmět: |
cancer biomarkers
Irreversible binding Analytical chemistry Biosensing Techniques biosensor Antibodies Article Analytical Chemistry interfaces Paramagnetism Antigen multivalent interactions Humans Surface plasmon resonance Magnetite Nanoparticles technologies ultrasensitive detection Range (particle radiation) biology Interleukin-6 Chemistry Prostate-Specific Antigen Surface Plasmon Resonance simulation Dissociation constant Immobilized Proteins gold nanoparticles strategies Biophysics biology.protein Kallikreins affinity Gold Antibody Superparamagnetism |
| Zdroj: | Analytical Chemistry. 84:10485-10491 |
| ISSN: | 1520-6882 0003-2700 |
| DOI: | 10.1021/ac3028257 |
| Popis: | We report here the first kinetic characterization of 1 μm diameter superparamagnetic particles (MP) decorated with over 100,000 antibodies binding to protein antigens attached to flat surfaces. Surface plasmon resonance (SPR) was used to show that these antibody-derivatized MPs (MP-Ab(2)) exhibit irreversible binding with 100-fold increased association rates compared to free antibodies. The estimated upper limit for the dissociation constant of MP-Ab(2) from the SPR sensor surface is 5 fM, compared to 3-8 nM for the free antibodies. These results are explained by up to 2000 interactions of MP-Ab(2) with protein-decorated surfaces. Findings are consistent with highly efficient capture of protein antigens in solution by the MP-Ab(2) and explain in part the utility of these beads for ultrasensitive protein detection into the fM and aM range. Aggregation of these particles on the SPR chip, probably due to residual magnetic microdomains in the particles, also contributes to ultrasensitive detection and may also help drive the irreversible binding. |
| Databáze: | OpenAIRE |
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