Recent advances in the study of chemical surfaces and interfaces by specular neutron reflection

Interfacial assembly of proteins and peptides: recent examples studied by neutron reflection

“…The principle of specular neutron reflection has been described in a number of reviews (Penfold & Thomas 1990;Lu et al 1996Lu et al , 2000Penfold et al 1997;Lu & Thomas 1998). The reflection of neutrons at a flat surface is comparable to light reflection.…”

“…However, the availability of significantly shorter neutron wavelengths enables smaller layer structures to be probed, with resolution down to the atomic and molecular level perpendicular to the interface. Neutrons' refractive indices are related to their scattering lengths, which are the physical constants that vary from one isotope to other (Penfold & Thomas 1990;Penfold et al 1997). The strong scattering by light atoms such as H, C, O and N emphasizes the advantageous feature of studying soft matter materials using this technique (Fragneto-Cusani 2001).…”

“…The kinematic approximation as outlined in equations (2.2) -(2.4) depicts a straightforward relation between neutron reflectivity in abstract space and interfacial structure in real space, and has been extensively used to analyse reflectivity profiles measured at the air -water interface by means of partial structure factors (Penfold & Thomas 1990;Lu et al 1996Lu et al , 2000Penfold et al 1997;Lu & Thomas 1998). However, the advantage of such an approach becomes less obvious when used for resolving the interfacial structure at the solid -water interface due to more complex structural correlations.…”

Interfacial recognition of human prostate-specific antigen by immobilized monoclonal antibody: effects of solution conditions and surface chemistry

“…The background was found to be typically around 3 Â 10 26 in D 2 O. The software called DATAFIT using the kinematic approximation as outlined in the previous review papers has been used to analyse reflectivity profiles by means of partial structure factors [22,23,30,31]. Fitting was initiated with a uniform layer followed by adding additional layers until a satisfactory fit was obtained.…”

New sources and instrumentation for neutrons in biology

“…For biomembrane studies instruments with high flux able to determine structures in the nanometer range are best suited and remarkable results have been obtained on instruments like NG1 or AND/R at NIST [40]; or the TOF instruments D17 at the ILL [41], or SURF at ISIS [42]. Reflectometers at other facilities as HMI, LLB, JINR or LANSCE have also been used regularly on biological systems.…”