Super-Stable, Highly Monodisperse Plasmonic Nanocrystals with 500 Gold Atoms: Au~500(SR)~120

Journal Article · Wed Jan 01 04:00:00 EST 2014 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja502327a· OSTI ID:1154797

Kumara, Chanaka ^[1]; Zuo, Xiaobing ^[2]; Ilavsky, Dr. Jan ^[3]; Chapman, Karena ^[2]; Cullen, David A ^[4]; Dass, Amala ^[1]

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1. University of Mississippi, The
2. Advanced Photon Source, Argonne National Laboratory (ANL)
3. Argonne National Laboratory (ANL)
4. ORNL

Determining the composition of plasmonic nanoparticles is challenging due to a deficiency in tools capable of accurately evaluating the number of atoms. Mass spectrometry plays a significant role in determining nanoparticle composition at the atomic level. Significant progress has been made in understanding ultra-small gold nanoparticles, like Au25(SR)18 and Au38(SR)24, with a Au core diameter of 0.97 and 1.3 nm, respectively. However, progress in small plasmonic nanoparticles (2 - 5 nm) is currently challenging, due in part to limitations in synthesizing monodisperse nanoparticles. Here, we report a plasmonic nanocrystal that is highly monodisperse, with an unprecedented variation of less than 20 gold atoms. The composition of the super-stable plasmonic nanocrystals at 115 kDa was determined to contain Au500 10SR120 3. The Au~500 system, named Faraduarate-500, is the largest size to be characterized using high resolution ESI mass spectrometry. Atomic pair distribution function (PDF) data shows that the local atomic structure is consistent with a face-centered cubic (fcc) or Marks decahedral arrangement. High resolution scanning transmission electron microscopy images show that the diameter is 2.4 0.1 nm. The radius of gyration measured by small angle X-ray scattering (SAXS), is 1.05 0.05 nm, and the size and the shape of SAXS molecular envelope are in agreement with TEM and PDF measurements.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1154797
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 20 Vol. 136; ISSN 0002-7863
• Country of Publication: United States
• Language: English