@article { ISI:000253926400026,
	title = {Top-down grafting of xyloglucan to gold monitored by QCM-D and AFM: Enzymatic activity and interactions with cellulose},
	journal = {BIOMACROMOLECULES},
	volume = {9},
	number = {3},
	year = {2008},
	month = {MAR},
	pages = {942-948},
	type = {Article},
	abstract = {<p>This study focuses on the manufacture and characterization of model surfaces consisting of end-grafted xyloglucan (XG), a naturally occurring polysaccharide, onto a gold substrate. The now well-established XET-technology was utilized for enzymatic incorporation of a thiol moiety at one end of the xyloglucan backbone. This functionalized macromolecule was subsequently top-down grafted to gold, forming a thiol-bonded xyloglucan brushlike layer. The grafting was monitored in situ with QCM-D, and a significant difference in the adsorbed/grafted amount between unmodified xyloglucan and the thiol-functionalized polymer was observed. The grafted surface was demonstrated to be accessible to enzyme digestion using the plant endo-xyloglucanase TmNXGI. The nanotribological properties toward cellulose of the untreated crystal, brush-modified surface, and enzyme-exposed surfaces were compared with a view to understanding the role of xyloglucan in friction reduction. Friction coefficients obtained by the AFM colloidal probe technique using a cellulose functionalized probe on the xyloglucan brush showed an increase of a factor of 2 after the enzyme digestion, and this result is interpreted in terms of surface roughness. Finally, the brush is shown to exhibit binding to cellulose despite its highly oriented nature.</p>},
	issn = {1525-7797},
	doi = {10.1021/bm701214e},
	author = {Nordgren, Niklas and Eklof, Jens and Zhou, Qi and Brumer, Harry and Rutland, Mark W.}
}
