کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5423869 1507947 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Adsorption of the cysteine-tryptophan dipeptide at the Au(110)/liquid interface studied using reflection anisotropy spectroscopy
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Adsorption of the cysteine-tryptophan dipeptide at the Au(110)/liquid interface studied using reflection anisotropy spectroscopy
چکیده انگلیسی
The adsorption of a cysteine-tryptophan dipeptide has been monitored at a Au(110)/electrolyte interface using reflection anisotropy spectroscopy. At −0.6 V the dipeptide adsorbed through the formation of Au-S bonds and a link between the NH2 group at the Au surface. As the applied potential was changed to + 0.6 V the NH2 group left the surface and the spectra suggest that two dipeptides form a disulphide bridge that binds to the Au surface. This event is accompanied by changes in the orientation of, and possibly interactions between, tryptophan moieties. Returning the applied potential to −0.6 V failed to re-establish the initial population of Au-S bonds and the changes induced in the region of the spectrum associated with the tryptophan's by the positive potentials were permanent on the time scale of an hour. Subtle changes associated with the tryptophan moieties indicate that the orientation of the tryptophans is very sensitive to the applied potential. Cycling of the potential showed a stable inter-conversion between Au-S bonds and Au-disulphide bonds at low scan rates, but at higher scan rates not all the broken disulphide bonds were able to reform. Irreversible changes were also observed in the tryptophan region of the spectrum during potential cycling.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 604, Issues 23–24, November 2010, Pages 2170-2176
نویسندگان
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