TY - JOUR
T1 - Mass spectrometric identification of water-soluble gold nanocluster fractions from sequential size-selective precipitation
AU - Yang, Xiupei
AU - Su, Yan
AU - Paau, Man Chin
AU - Choi, Martin M.F.
N1 - Financial support from the HKBU Faculty Research Grant (Project No. FRG2/08-09/077) is gratefully acknowledged. M.C. Paau acknowledges the receipt of a postgraduate studentship from the Additional UGC-funded Research Postgraduate Placesin the area of Environmental and Human Health Risk Assessment of Persistent Toxic Substance. The HRTEM used in this work was supported by the Special Equipment Grant from the University Grants Committee of the Hong Kong Special Administrative Region, China (Grant SEG_HKBU06).
PY - 2012/2/7
Y1 - 2012/2/7
N2 - This paper presents a simple and convenient methodology to separate and characterize water-soluble gold nanocluster stabilized with penicillamine ligands (AuNC-SR) in aqueous medium by sequential size-selective precipitation (SSSP) and mass spectrometry (MS). The highly polydisperse crude AuNC-SR product with an average core diameter of 2.1 nm was initially synthesized by a one-phase solution method. AuNCs were then precipitated and separated successively from larger to smaller ones by progressively increasing the concentration of acetone in the aqueous AuNCs solution. The SSSP fractions were analyzed by UV-vis spectroscopy, matrix-assisted laser desorption/ionization time-of-flight-MS, and thermogravimetric analysis (TGA). The MS and TGA data confirmed that the fractions precipitated from 36, 54, 72, and 90% v/v acetone (F 36%, F 54%, F 72%, and F 90%) comprised families of close core size AuNCs with average molecular formulas of Au 38(SR) 18, Au 28(SR) 15, Au 18(SR) 12, and Au 11(SR) 8, respectively. In addition, F 36%, F 54%, F 72%, and F 90% contained also the typical magic-sized gold nanoparticles of Au 38, Au 25, Au 18, and Au 11, respectively, together with some other AuNCs. This study shed light on the potential use of SSSP for simple and large-scale preliminary separation of polydisperse water-soluble AuNCs into different fractions with a relatively narrower size distribution.
AB - This paper presents a simple and convenient methodology to separate and characterize water-soluble gold nanocluster stabilized with penicillamine ligands (AuNC-SR) in aqueous medium by sequential size-selective precipitation (SSSP) and mass spectrometry (MS). The highly polydisperse crude AuNC-SR product with an average core diameter of 2.1 nm was initially synthesized by a one-phase solution method. AuNCs were then precipitated and separated successively from larger to smaller ones by progressively increasing the concentration of acetone in the aqueous AuNCs solution. The SSSP fractions were analyzed by UV-vis spectroscopy, matrix-assisted laser desorption/ionization time-of-flight-MS, and thermogravimetric analysis (TGA). The MS and TGA data confirmed that the fractions precipitated from 36, 54, 72, and 90% v/v acetone (F 36%, F 54%, F 72%, and F 90%) comprised families of close core size AuNCs with average molecular formulas of Au 38(SR) 18, Au 28(SR) 15, Au 18(SR) 12, and Au 11(SR) 8, respectively. In addition, F 36%, F 54%, F 72%, and F 90% contained also the typical magic-sized gold nanoparticles of Au 38, Au 25, Au 18, and Au 11, respectively, together with some other AuNCs. This study shed light on the potential use of SSSP for simple and large-scale preliminary separation of polydisperse water-soluble AuNCs into different fractions with a relatively narrower size distribution.
UR - http://www.scopus.com/inward/record.url?scp=84863040254&partnerID=8YFLogxK
U2 - 10.1021/ac2029908
DO - 10.1021/ac2029908
M3 - Journal article
C2 - 22229882
AN - SCOPUS:84863040254
SN - 0003-2700
VL - 84
SP - 1765
EP - 1771
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 3
ER -