Limits...
First-principles investigation of Ag-doped gold nanoclusters.

Zhang XD, Guo ML, Wu D, Liu PX, Sun YM, Zhang LA, She Y, Liu QF, Fan FY - Int J Mol Sci (2011)

Bottom Line: The electronic structure of a stable Au(20) cluster can be modulated by incorporating Ag, and the HOMO-LUMO gap of Au(20-) (n)Ag(n) clusters is modulated due to the incorporation of Ag electronic states in the HOMO and LUMO.Furthermore, the results of the imaginary part of the dielectric function indicate that the optical transition of gold clusters is concentration-dependent and the optical transition between HOMO and LUMO shifts to the low energy range as the Ag atom increases.These calculated results are helpful for the design of gold cluster-based biomaterials, and will be of interest in the fields of radiation medicine, biophysics and nanoscience.

View Article: PubMed Central - PubMed

Affiliation: Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China; E-Mails: wudi521wan@163.com (D.W.); pharm8888@yahoo.com.cn (P.-X.L.); yuanmings1962@163.com (Y.-M.S.); zhangla43@yahoo.com.cn (L.-A.Z.); yi_she2005@yahoo.com.cn (Y.S.); qingfenliu@yahoo.com.cn (Q.-F.L.).

ABSTRACT
Gold nanoclusters have the tunable optical absorption property, and are promising for cancer cell imaging, photothermal therapy and radiotherapy. First-principle is a very powerful tool for design of novel materials. In the present work, structural properties, band gap engineering and tunable optical properties of Ag-doped gold clusters have been calculated using density functional theory. The electronic structure of a stable Au(20) cluster can be modulated by incorporating Ag, and the HOMO-LUMO gap of Au(20-) (n)Ag(n) clusters is modulated due to the incorporation of Ag electronic states in the HOMO and LUMO. Furthermore, the results of the imaginary part of the dielectric function indicate that the optical transition of gold clusters is concentration-dependent and the optical transition between HOMO and LUMO shifts to the low energy range as the Ag atom increases. These calculated results are helpful for the design of gold cluster-based biomaterials, and will be of interest in the fields of radiation medicine, biophysics and nanoscience.

Show MeSH

Related in: MedlinePlus

The tunable imaginary part of dielectric function ɛ2(ω) of Au20−nAgn clusters.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3116168&req=5

f4-ijms-12-02972: The tunable imaginary part of dielectric function ɛ2(ω) of Au20−nAgn clusters.

Mentions: Figure 4 shows the imaginary part of dielectric function ɛ2(ω) of Au20−nAgn clusters. Ag incorporation induces some obvious variations of optical transitions. Firstly, E1 has gradually disappeared, which can be related to the red-shift of E2 and further inhibition of the intrinsic optical transition of E1. Secondly, E2 shows the tunable optical properties with the increasing Ag incorporation. The E2 of Au20, Au19Ag1, Au18Ag2, Au17Ag3, and Au16Ag4 is 2.51, 2.35, 2.25, 2.07, and 2.01 eV, respectively. To understand these optical phenomena in detail, it is necessary to analyze the optical transition by electronic states.


First-principles investigation of Ag-doped gold nanoclusters.

Zhang XD, Guo ML, Wu D, Liu PX, Sun YM, Zhang LA, She Y, Liu QF, Fan FY - Int J Mol Sci (2011)

The tunable imaginary part of dielectric function ɛ2(ω) of Au20−nAgn clusters.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3116168&req=5

f4-ijms-12-02972: The tunable imaginary part of dielectric function ɛ2(ω) of Au20−nAgn clusters.
Mentions: Figure 4 shows the imaginary part of dielectric function ɛ2(ω) of Au20−nAgn clusters. Ag incorporation induces some obvious variations of optical transitions. Firstly, E1 has gradually disappeared, which can be related to the red-shift of E2 and further inhibition of the intrinsic optical transition of E1. Secondly, E2 shows the tunable optical properties with the increasing Ag incorporation. The E2 of Au20, Au19Ag1, Au18Ag2, Au17Ag3, and Au16Ag4 is 2.51, 2.35, 2.25, 2.07, and 2.01 eV, respectively. To understand these optical phenomena in detail, it is necessary to analyze the optical transition by electronic states.

Bottom Line: The electronic structure of a stable Au(20) cluster can be modulated by incorporating Ag, and the HOMO-LUMO gap of Au(20-) (n)Ag(n) clusters is modulated due to the incorporation of Ag electronic states in the HOMO and LUMO.Furthermore, the results of the imaginary part of the dielectric function indicate that the optical transition of gold clusters is concentration-dependent and the optical transition between HOMO and LUMO shifts to the low energy range as the Ag atom increases.These calculated results are helpful for the design of gold cluster-based biomaterials, and will be of interest in the fields of radiation medicine, biophysics and nanoscience.

View Article: PubMed Central - PubMed

Affiliation: Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China; E-Mails: wudi521wan@163.com (D.W.); pharm8888@yahoo.com.cn (P.-X.L.); yuanmings1962@163.com (Y.-M.S.); zhangla43@yahoo.com.cn (L.-A.Z.); yi_she2005@yahoo.com.cn (Y.S.); qingfenliu@yahoo.com.cn (Q.-F.L.).

ABSTRACT
Gold nanoclusters have the tunable optical absorption property, and are promising for cancer cell imaging, photothermal therapy and radiotherapy. First-principle is a very powerful tool for design of novel materials. In the present work, structural properties, band gap engineering and tunable optical properties of Ag-doped gold clusters have been calculated using density functional theory. The electronic structure of a stable Au(20) cluster can be modulated by incorporating Ag, and the HOMO-LUMO gap of Au(20-) (n)Ag(n) clusters is modulated due to the incorporation of Ag electronic states in the HOMO and LUMO. Furthermore, the results of the imaginary part of the dielectric function indicate that the optical transition of gold clusters is concentration-dependent and the optical transition between HOMO and LUMO shifts to the low energy range as the Ag atom increases. These calculated results are helpful for the design of gold cluster-based biomaterials, and will be of interest in the fields of radiation medicine, biophysics and nanoscience.

Show MeSH
Related in: MedlinePlus