Hidden Components in Aqueous "Gold-144" Fractionated by PAGE: High-Resolution Orbitrap ESI-MS Identifies the Gold-102 and Higher All-Aromatic Au-pMBA Cluster Compounds.
Experimental and theoretical evidence reveals the resilience and stability of the larger aqueous gold clusters protected with p-mercaptobenzoic acid ligands (pMBA) of composition Aun(pMBA)p or (n, p). The Au144(pMBA)60, (144, 60), or gold-144 aqueous gold cluster is considered special because of its high symmetry, abundance, and icosahedral structure as well as its many potential uses in material and biological sciences. Yet, to this date, direct confirmation of its precise composition and total structure remains elusive. Results presented here from characterization via high-resolution electrospray ionization mass spectrometry on an Orbitrap instrument confirm Au102(pMBA)44 at isotopic resolution. Further, what usually appears as a single band for (144, 60) in electrophoresis (PAGE) is shown to also contain the (130, 50), recently determined to have a truncated-decahedral structure, and a (137, 56) component in addition to the dominant (144, 60) compound of chiral-icosahedral structure. This finding is significant in that it reveals the existence of structures never before observed in all-aromatic water-soluble species while pointing out the path toward elucidation of the thermodynamic control of protected gold nanocrystal formation.
Department of Physics & Astronomy, University of Texas , San Antonio, Texas 78249, United States.
Marcos M
MM
Alvarez
ThermoFisher Scientific , 355 River Oaks Parkway, San Jose, California 95134, United States.
Jenny
J
Chen
Department of Physics & Astronomy, University of Texas , San Antonio, Texas 78249, United States.
Germán
G
Plascencia-Villa
Department of Physics & Astronomy, University of Texas , San Antonio, Texas 78249, United States.
David M
DM
Black
RCMI Protein Biomarkers Core, University of Texas , San Antonio, Texas 78249, United States.
Wendell P
WP
Griffith
Department of Physics & Astronomy, University of Texas , San Antonio, Texas 78249, United States.|Instituto de Física, Universidad Nacional Autónoma de México , Apartado Postal 20-364, 01000 México, D. F, México.
Ignacio L
IL
Garzón
Department of Physics & Astronomy, University of Texas , San Antonio, Texas 78249, United States.
Miguel
M
José-Yacamán
Department of Biochemistry, University of Texas Health Science Center , San Antonio, Texas 78229, United States.
Borries
B
Demeler
Department of Physics & Astronomy, University of Texas , San Antonio, Texas 78249, United States.
Robert L
RL
Whetten
D001565:Benzoates / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006046:Gold / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008956:Models, Chemical; D011522:Protons; D012964:Sodium / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D001565:Benzoates; D007477:Ions; D011522:Protons; D013438:Sulfhydryl Compounds; D014867:Water; C013594:4-mercaptobenzoate; D006046:Gold; D012964:Sodium