کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1684979 | 1010541 | 2007 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Heâ interaction with soft matter surfaces: Ultra thin l-cysteine films
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سطوح، پوششها و فیلمها
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
We report first results about the interaction of a Heâ beam with nanometer thick layers of l-cysteine, a fundamental amino-acid, deposited under ultra high vacuum conditions on Cu and Au surfaces. Electronic properties of adsorbed molecules have been investigated by metastable deexcitation spectroscopy (MDS). Deexcitation of Heâ on molecular layers gives rise to well defined Penning ionization spectra. In these spectra, we distinguish contributions of the molecules strongly bound to the surface through the thiol group and of molecules weakly bound to the surface, as for example those belonging to multilayers. The beam (whose intensity on the sample is of the order of 1011Â at/s with a spot diameter of 1Â mm) induces slow rate desorption of weakly bound molecules. Mild annealing to 330Â K induces the desorption of weakly bound molecules as well. Cleavage of intra-molecular bonds is observed for annealing temperatures above 420Â K. Beam-induced damage of first layer molecules appears not significant on the time scale (tens of seconds) of the MDS experiment. The data demonstrate the full applicability of MDS to the investigation of self-assembled monolayers of small biomolecules.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 256, Issue 1, March 2007, Pages 324-327
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 256, Issue 1, March 2007, Pages 324-327
نویسندگان
M. Canepa, P. Pelori, L. Lavagnino, F. Bisio, R. Moroni, S. Terreni, L. Mattera,