TY - JOUR A1 - Jain, V. A1 - Kjaervik, Marit A1 - Bahr, S. A1 - Dietrich, P. A1 - Meyer, M. A1 - Thissen, A. A1 - Linford, M. R. T1 - Bovine serum albumin, aqueous solution, by near-ambient pressure XPS N2 - Near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) is a less traditional form of XPS that allows samples to be analyzed at relatively high pressures, i.e., at greater than 2500 Pa. With NAP-XPS, XPS can probe moderately volatile liquids, biological samples, porous materials, and/or polymeric materials that outgas significantly. In this submission, we show survey, C 1s, O 1s, and N 1s narrow scans from an aqueous solution of a common protein, bovine serum albumin. The C 1s peak envelope is well fit to four symmetric peaks of equal width that correspond to carbon bonded to carbon and hydrogen (C-1), carbon singly bonded to oxygen (C-2), carbonyl and/or amide carbon (C-3), and carboxyl carbon (C-4). Two possible peak fits are considered for the N 1s and O 1s peak envelopes. The N 1s signal is fit to four peaks that correspond to amine (—NH2), Amide (OvCZNH2), ammonium (—NH3 +), and N2(g) nitrogen, and alternatively to three peaks that correspond to amine, amide, and N2(g) nitrogen. The O 1s peak envelope is similarly fit to three and four components. KW - NAP-XPS KW - BSA KW - Bovine serum albumin KW - XPS KW - Near-ambient pressure PY - 2019 DO - https://doi.org/10.1116/1.5055229 VL - 26 IS - 1 SP - 014027 PB - American Vacuum Society CY - New York, USA AN - OPUS4-48655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kjaervik, Marit A1 - Müller, Anja A1 - Dietrich, P. A1 - Thissen, A. A1 - Bahr, S. A1 - Ritter, B. A1 - Kemnitz, E. A1 - Unger, Wolfgang T1 - Detection of suspended nanoparticles with near-ambient pressure x-ray photoelectron spectroscopy N2 - Two systems of suspended nanoparticles have been studied with near-ambient pressure x-ray photoelectron spectroscopy: silver nanoparticles in water and strontium fluoride—calcium fluoride core-shell nanoparticles in ethylene glycol. The corresponding dry samples were measured under ultra high vacuum for comparison. The results obtained under near-ambient pressure were overall comparable to those obtained under ultra high vacuum, although measuring silver nanoparticles in water requires a high pass energy and a long acquisition time. A shift towards higher binding energies was found for the silver nanoparticles in aqueous Suspension compared to the corresponding dry sample, which can be assigned to a change of surface potential at the water-nanoparticle interface. The shell-thickness of the core-shell nanoparticles was estimated based on simulated spectra from the National Institute of Standards and Technology database for simulation of electron spectra for surface analysis. With the instrumental set-up presented in this paper, nanoparticle suspensions in a suitable Container can be directly inserted into the analysis chamber and measured without prior sample preparation. KW - Nanoparticles KW - Suspensions KW - Core-shell nanoparticles KW - NAP-XPS PY - 2017 DO - https://doi.org/10.1088/1361-648X/aa8b9d SN - 1361-648X SN - 0953-8984 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. VL - 29 IS - 47 SP - 474002, 1 EP - 474002, 9 PB - IOP Publishing CY - UK AN - OPUS4-42951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -