Qiaohong Zhang, Chen Chen, Min Wang, Jiaying Cai, Jie Xu* and Chungu Xia*
* Corresponding authors: Jie Xu xujie@dicp.ac.cn - Chungu Xia cgxia@licp.cas.cn
Nanoscale Research Letters 2011, 6:586 doi:10.1186/1556-276X-6-586