Thymine-protected gold nanoparticles: assembly and disassembly of gold nanoparticles in the presence of Hg2+.
In this paper, we describe thymine-protected gold nanoparticles. Assembly of thymine-protected gold nanoparticles into interconnected network was observed by gradual addition of Hg2+. Moreover, the plasmon absorption intensity varied almost linearly with the concentration of Hg2+, indicating that thymine-protected gold nanoparticles are potentially useful for signaling Hg2+. It is interesting to note that disassembly of gold nanoparticles occurred when the concentration of Hg2+ in the solution was high. It is proposed that the assembly of gold nanoparticles is due to the coordination of Hg2+ with thymine groups of adjacent nanoparticles, while the disassembly of gold nanoparticles is attributed to the electrostatic repulsion among the nanoparticles with positive charges which are generated through the coordination of Hg2+ with thymine groups absorbed on the surface of each nanoparticle.
Liu
Lei
L
Beijing National Laboratory for Molecular Sciences, Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Zhang
De-Qing
DQ
Zheng
Xiao-Ping
XP
Wang
Zhuo
Z
Zhu
Dao-Ben
DB