Atomic Force Spectroscopy

J. Kaur, K.V. Singh, A.H. Schmid, G.C. Varshney, C.R. Suri, and M. Raje, Atomic force spectroscopy-based study of antibody pesticide interactions for characterization of immunosensor surface. Biosens. Bioelectron. 20, 284—293 (2004). 

Atomic force spectroscopy shows that when only the polymer-substrate surface is modified, parallel orientation of the nanoscopic cylinders is observed in the 137 nm thick film (see Figure 4.34(a)) because of the lower surface energy of the polystyrene block. However, the presence of a random copolymer at both the polymer-substrate and the polymer-air interfaces eliminates the preferential... 

Zlatanova J, Lindsay SM, Leuba SH (2000) Single molecule force spectroscopy in biology using atomic force spectroscopy. Prog. Biophys. Mol. Biol. 74 37-61... 

The ramifications of nanotechnology in the food arena have yet to be fully realized. This requires further research into biopolymer assembly behavior and applications of nanomaterials in the food industry. Researchers should keep abreast of the development of research tools and what is being done to push resolution limits for techniques such as atomic force spectroscopy or the synchrotron coupled to various spectroscopic techniques and higher resolution microscopy. New techniques should be exploited and the knowledge gained used to understand the dynamics and interactions of food materials at the single-molecule level and to describe assembly behavior in quantitative thermodynamic terms. There are questions about the interactions of nanoparticles with the food matrix and within the human body. These questions need to be addressed by future research (Simon and Joner, 2008 Sletmoen et ah, 2008). 

Another area of technology with an enormous application potential is nanotechnology. Currently, nanotechnology is developing at a dramatic rate as atomic force spectroscopy provides it with instruments to model atoms and molecules and also to control them. Because of their enormous specific surface area in relation to their volume, particles as small as a millionth of a millimeter have different chemical and physical... 

Figure 9.2 Empirical force vs. distance (z) curve that reflects the type of interaction between the AFM tip and the sample during measurements using distinct imaging modes. (Reprinted with permission from Journal of Adehsion Science and Technology, Application of atomic force spectroscopy (AFS) to studies of adhesion phenomena a review by F. L. Leite, P. S. P. Herrmann et al., 19, 3-5, 365-405. Copyright (2005) Brill)...

AFM can be used to determine the dependence of the interaction on the probe-sample distance at a given location [85], in so-called atomic force spectroscopy (AFS). Both the... 

Figure 9.24 Force curve obtained when extending chains ofPOEA from the chrome surface in water with frequency of jumps < 1 pm s I no tip-POEA interactions II film being compressed lll/IV repulsive contact with the substrate V pull-of force due to surface adhesion VI cantilever pulls off the surface VII attractive peak due to stretching of POEA chains. (Reprinted with permission from Microscopy and Microanaiysis, Atomic Force Spectroscopy on Poly(o-ethoxyaniline) Nanostructured Films Sensing Nonspecific Interactions byF.L. Leite, C.E. Borato, W.T.L. da Silva, P.S.P. Herrmann, O.N. Oliveira Jr., L.H.C. Mattoso, 13, 304 (Copyright 2007).

F.L. Leite, C.E. Borato, W.T.L Silva, P.S.P Herrmann, O.N. Oliveira Jr, and L.H.C. Mattoso, Atomic force spectroscopy on poly(o-ethoxyaniline) nanostructured films sensing nonspecific interactions, Microsc. Microanal., 13, 304-312 (2007). 

Wackerbarth, H. Schon, R Bindrich, U., Preparation and characterization of multilayer coated microdroplets Droplet deformation simultaneously probed by atomic force spectroscopy and optical detection. Langmuir (2009) 25, 2636-2640. 

Abstract Atomic force spectroscopy (AFM)-based single-molecule force spectroscopy (SMFS) was invented in the 1990s. Since then, SMFS has been developed into a powerful tool to study the inter- and intra-molecular interactions of macro-molecules. Using SMFS, a number of problems in the field of supramolecular chemistry and mechanochemistry have been studied at the single-molecule level, which are not accessible by traditional ensemble characterization methods. In this review, the principles of SMFS are introduced, followed by the discussion of several problems of contemporary interest at the interface of supramolecular chemistry and mechanochemistry of macromolecules, including single-chain elasticity of macromolecules, interactions between water and macromolecules, interactions between macromolecules and solid surface, and the interactions in supramolecular polymers. 

Ganchev, D. N., Rijkers, D. T. S., Snel, M. M. E., Killian, J. A., and de Kruijff, B. 2004. Strength of integration of transmembrane alpha-helical peptides in lipid bilayers as determined by atomic force spectroscopy. Biochemistry 43,14987-14993. 

A relatively new TA technique, known as micro-thermal analysis (/r-TA) can be considered as a coupled TA technique since usually two or more measurements are made simultaneously. /r-TA combines the imaging capabilities of atomic force spectroscopy with a form of localized TA, and this technique offers nanotechnological TA applications. 

L. Adams, M. J., Application of Colloidal Probe Atomic Force Spectroscopy to the Adhesion of Thin Films of Viscous and Viscoelastic Silicone Fluids. Langmuir 2011, 27,11489-11500. 

The application of AFM and other techniques has been discussed in general terms by several workers [350-353]. Other complementary techniques covered in these papers include FT-IR spectroscopy, Raman spectroscopy, NMR spectroscopy, surface analysis by spectroscopy, GC-MS, scanning tunnelling microscopy, electron crystallography, X-ray studies using synchrotron radiation, neutron scattering techniques, mixed crystal infrared spectroscopy, SIMS, and XPS. Applications of atomic force spectroscopy to the characterisation of the following polymers have been reported polythiophene [354], nitrile rubbers [355], perfluoro copolymers of cyclic polyisocyanurates of hexamethylene diisocyanate and isophorone diisocyanate [356], perfluorosulfonate [357], vinyl polymers... 

Kocevar K, Musevic I (2002) Surface-induced nematic and smectic order at a liquid-crystal-sUanated-glass interface observed by atomic force spectroscopy and Brewster angle ellipsometry. Phys Rev E 65 021703... 

AFS atomic force spectroscopy CLLE continuous liquid-liquid extraction... 

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