TY  - JOUR
AU  - Wetzel, Oliver
AU  - Hosseini, Shabnam
AU  - Loza, Kateryna
AU  - Heggen, Marc
AU  - Prymak, Oleg
AU  - Bayer, Peter
AU  - Beuck, Christine
AU  - Schaller, Torsten
AU  - Niemeyer, Felix
AU  - Weidenthaler, Claudia
AU  - Epple, Matthias
TI  - Metal–Ligand Interface and Internal Structure of Ultrasmall Silver Nanoparticles (2 nm)
JO  - The journal of physical chemistry  / B
VL  - 125
IS  - 21
SN  - 1520-5207
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2021-02924
SP  - 5645 - 5659
PY  - 2021
AB  - Ultrasmall silver nanoparticles were prepared by reduction with NaBH4 and surface-terminated with glutathione (GSH). The particles had a solid core diameter of 2 nm as shown by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). NMR-DOSY gave a hydrodynamic diameter of 2 to 2.8 nm. X-ray photoelectron spectroscopy (XPS) showed that silver is bound to the thiol group of the central cysteine in glutathione under partial oxidation to silver(+I). In turn, the thiol group is deprotonated to thiolate. X-ray powder diffraction (XRD) together with Rietveld refinement confirmed a twinned (polycrystalline) fcc structure of ultrasmall silver nanoparticles with a lattice compression of about 0.9% compared to bulk silver metal. By NMR spectroscopy, the interaction between the glutathione ligand and the silver surface was analyzed, also with 13C-labeled glutathione. The adsorbed glutathione is fully intact and binds to the silver surface via cysteine. In situ1H NMR spectroscopy up to 85 °C in dispersion showed that the glutathione ligand did not detach from the surface of the silver nanoparticle, i.e. the silver–sulfur bond is remarkably strong. The ultrasmall nanoparticles had a higher cytotoxicity than bigger particles in in vitro cell culture with HeLa cells with a cytotoxic concentration of about 1 μg mL–1 after 24 h incubation. The overall stoichiometry of the nanoparticles was about Ag∼250GSH∼155.
LB  - PUB:(DE-HGF)16
C6  - 34029093
UR  - <Go to ISI:>//WOS:000661116600019
DO  - DOI:10.1021/acs.jpcb.1c02512
UR  - https://juser.fz-juelich.de/record/893912
ER  -