A Physical Approach to Reduce Nonspecific Adhesion in Molecular Recognition Atomic Force Microscopy
| Autor: | Laurens Kuipers, O.H. Willemsen, Bart G. de Grooth, Jan Greve, M.M.E. Snel, Carl G. Figdor |
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| Přispěvatelé: | Optical Sciences |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Cantilever
Chemistry Computers Static Electricity Biophysics Thermal fluctuations Nanotechnology Adhesion Conical surface Intercellular Adhesion Molecule-1 Microscopy Atomic Force Antibodies Molecular recognition Molecular Force Microscopy for the analysis of bio-interfaces Chemical physics Microscopy DLVO theory Aluminum Silicates Mica Algorithms Protein Binding Research Article |
| Zdroj: | Biophysical Journal, 76, 2, pp. 716-724 Biophysical journal, 76(2), 716-724. Biophysical Society Biophysical Journal, 76, 716-724. Biophysical society Biophysical Journal, 76, 716-724 Scopus-Elsevier |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/s0006-3495(99)77238-3 |
| Popis: | Atomic force microscopy is one of the few techniques that allow analysis of biological recognition processes at the single-molecule level. A major limitation of this approach is the nonspecific interaction between the force sensor and substrate. We have modeled the nonspecific interaction by looking at the interaction potential between a conical Si3N4 tip with a spherical end face and a mica surface in solution, using DLVO (Derjaguin, Landau, Verwey, Overbeek) theory and numerical calculations. Insertion of the tip-sample potential in a simulation of an approach-retract cycle of the cantilever gives the well-known force-distance curve. Simulating a force-distance curve at low salt concentration predicts a discrete hopping of the tip, caused by thermal fluctuations. This hopping behavior was observed experimentally and gave rise to a novel approach to making measurements in adhesion mode that essentially works in the repulsive regime. The distance between tip and sample will still be small enough to allow spacer-involved specific interactions, and the percentage of nonspecific interactions of the bare tip with the mica is minimized. We have validated this physical model by imaging intercellular adhesion molecule 1 (ICAM-1) antigen with a tip functionalized with anti-ICAM-1 antibody. The measurement demonstrated that a significant decrease in the number of nonspecific interactions was realized, and the topographical image quality and the specific bonding capability of the tip were not affected. |
| Databáze: | OpenAIRE |
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