TY - JOUR
T1 - Toward Smaller Aqueous-Phase Plasmonic Gold Nanoparticles
T2 - High-Stability Thiolate-Protected 4.5 nm Cores
AU - Hoque, M. Mozammel
AU - Mayer, Kathryn M.
AU - Ponce, Arturo
AU - Alvarez, M. M.
AU - Whetten, Robert L.
N1 - Funding Information:
The authors thank Dr. M. J. Yacaman for access to use UV–vis spectroscopy, Mr. Sean Mullins for helping with Au 1289 structure-factor calculation, and Mr. James W. Boyd for helping with FTIR data collection. Microscopy was supported by the Kleberg Advanced Microscopy Center and the Nanotechnology and Human Health Core at UTSA, through the National Center for Research Resources (5G12RR013646-12). We also give thanks for support from Department of Defense no. 72489-RT-REP and The Welch Foundation no. AX-1857, “Fundamental Chemical Research on Larger Molecular Noble Metal Clusters”.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/8/13
Y1 - 2019/8/13
N2 - Most applications of aqueous plasmonic gold nanoparticles benefit from control of the core size and shape, control of the nature of the ligand shell, and a simple and widely applicable preparation method. Surface functionalization of such nanoparticles is readily achievable but is restricted to water-soluble ligands. Here we have obtained highly monodisperse and stable smaller aqueous gold nanoparticles (core diameter 4.5 nm), prepared from citrate-tannate precursors via ligand exchange with each of three distinct thiolates: 11-mercaptoundecanoic acid, α-R-lipoic acid, and para-mercaptobenzoic acid. These are characterized by UV-vis spectroscopy for plasmonic properties; Fourier transform infrared (FTIR) spectroscopy for ligand-exchange confirmation; X-ray diffractometry for structural analysis; and high-resolution transmission electron microscopy for structure and size determination. Chemical reduction induces a blueshift, maximally +0.02 eV, in the localized surface plasmon resonance band; this is interpreted as an electronic (-) charging of the monolayer-protected cluster (MPC) gold core, corresponding to a -0.5 V change in electrochemical potential.
AB - Most applications of aqueous plasmonic gold nanoparticles benefit from control of the core size and shape, control of the nature of the ligand shell, and a simple and widely applicable preparation method. Surface functionalization of such nanoparticles is readily achievable but is restricted to water-soluble ligands. Here we have obtained highly monodisperse and stable smaller aqueous gold nanoparticles (core diameter 4.5 nm), prepared from citrate-tannate precursors via ligand exchange with each of three distinct thiolates: 11-mercaptoundecanoic acid, α-R-lipoic acid, and para-mercaptobenzoic acid. These are characterized by UV-vis spectroscopy for plasmonic properties; Fourier transform infrared (FTIR) spectroscopy for ligand-exchange confirmation; X-ray diffractometry for structural analysis; and high-resolution transmission electron microscopy for structure and size determination. Chemical reduction induces a blueshift, maximally +0.02 eV, in the localized surface plasmon resonance band; this is interpreted as an electronic (-) charging of the monolayer-protected cluster (MPC) gold core, corresponding to a -0.5 V change in electrochemical potential.
UR - http://www.scopus.com/inward/record.url?scp=85070539403&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85070539403&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.9b01908
DO - 10.1021/acs.langmuir.9b01908
M3 - Article
C2 - 31299160
AN - SCOPUS:85070539403
SN - 0743-7463
VL - 35
SP - 10610
EP - 10617
JO - Langmuir
JF - Langmuir
IS - 32
ER -