東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Fluorescent noble metal nanoclusters.

Zheng, Jie.

FindBook

Google Book

Amazon

博客來

Fluorescent noble metal nanoclusters.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Fluorescent noble metal nanoclusters./
作者:	Zheng, Jie.
面頁冊數:	169 p.
附註:	Source: Dissertation Abstracts International, Volume: 67-03, Section: B, page: 1465.
Contained By:	Dissertation Abstracts International67-03B.
標題:	Chemistry, Physical. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3212325
ISBN:	9780542607929

Fluorescent noble metal nanoclusters.
Zheng, Jie.

Fluorescent noble metal nanoclusters. - 169 p.

Source: Dissertation Abstracts International, Volume: 67-03, Section: B, page: 1465.

Thesis (Ph.D.)--Georgia Institute of Technology, 2005.

Water-soluble fluorescent metallic clusters at sizes comparable to the Fermi wavelength of an electron (&sim;0.5 nm for gold and silver) were created and their photophysical properties were investigated at the bulk and single molecule levels. We employed biocompatible dendrimer and peptide to prepare a series of strong fluorescent gold and silver clusters with chemical or photo reduction methods. Facilitated by the well-defined dendrimer size, electrospray ionization mass spectrometry indicates that the fluorescent silver nanocluster size ranges from 2 to 8 Ag atoms. The correlation of emission energy with the number of atoms, N, in each gold nanocluster is quantitatively fit for the smallest nanoclusters with no adjustable parameters by the simple scaling relation of EFermi/N1/3, in which EFermi is the Fermi energy of bulk gold. The transition energy scaling inversely with cluster radius indicates that electronic structure can be well described with the spherical jellium model and further demonstrates that these nanomaterials are "multi-electron artificial atoms". Fluorescence from these small metal clusters can be considered protoplasmonic, molecular transitions of the free conduction electrons before the onset of collective dipole oscillations occurring when a continuous density of states is reached. In addition, very strong single molecular Stokes and anti-Stokes Raman enhancement by fluorescent silver clusters was observed. Pushing to larger sizes, we also created &sim;2nm diameter glutathione encapsulated luminescent gold nanoparticles. Distinct from similarly sized but nonluminescent gold nanoparticles, these 2 nm gold nanoparticles show bright, long lifetime emission but no plasmon absorption. The emission might arise from charge transfer between gold atoms and the thiol ligand. Providing the "missing link" between atomic and nanoparticle behavior in noble metals, these highly fluorescent, water-soluble gold and silver nanoclusters offer complementary transition energy size scalings at smaller dimensions than do semiconductor quantum dots. The unique discrete excitation and emission and strong Stokes and anti-Stokes Raman enhancement coupled with facile creation in aqueous solution open new opportunities for noble metal nanoclusters as biological labels, energy transfer pairs, and other light emitters in nanoscale electronics.

ISBN: 9780542607929Subjects--Topical Terms:

560527
Chemistry, Physical.

Fluorescent noble metal nanoclusters.
LDR:03238nmm 2200277 4500 001 1827228
005 20061222091127.5
008 130610s2005 eng d
020 $a 9780542607929
035 $a (UnM)AAI3212325
035 $a AAI3212325
040 $a UnM $c UnM
100 1 $a Zheng, Jie. $3 1058666
245 1 0 $a Fluorescent noble metal nanoclusters.
300 $a 169 p.
500 $a Source: Dissertation Abstracts International, Volume: 67-03, Section: B, page: 1465.
500 $a Adviser: Robert M. Dickson.
502 $a Thesis (Ph.D.)--Georgia Institute of Technology, 2005.
520 $a Water-soluble fluorescent metallic clusters at sizes comparable to the Fermi wavelength of an electron (&sim;0.5 nm for gold and silver) were created and their photophysical properties were investigated at the bulk and single molecule levels. We employed biocompatible dendrimer and peptide to prepare a series of strong fluorescent gold and silver clusters with chemical or photo reduction methods. Facilitated by the well-defined dendrimer size, electrospray ionization mass spectrometry indicates that the fluorescent silver nanocluster size ranges from 2 to 8 Ag atoms. The correlation of emission energy with the number of atoms, N, in each gold nanocluster is quantitatively fit for the smallest nanoclusters with no adjustable parameters by the simple scaling relation of EFermi/N1/3, in which EFermi is the Fermi energy of bulk gold. The transition energy scaling inversely with cluster radius indicates that electronic structure can be well described with the spherical jellium model and further demonstrates that these nanomaterials are "multi-electron artificial atoms". Fluorescence from these small metal clusters can be considered protoplasmonic, molecular transitions of the free conduction electrons before the onset of collective dipole oscillations occurring when a continuous density of states is reached. In addition, very strong single molecular Stokes and anti-Stokes Raman enhancement by fluorescent silver clusters was observed. Pushing to larger sizes, we also created &sim;2nm diameter glutathione encapsulated luminescent gold nanoparticles. Distinct from similarly sized but nonluminescent gold nanoparticles, these 2 nm gold nanoparticles show bright, long lifetime emission but no plasmon absorption. The emission might arise from charge transfer between gold atoms and the thiol ligand. Providing the "missing link" between atomic and nanoparticle behavior in noble metals, these highly fluorescent, water-soluble gold and silver nanoclusters offer complementary transition energy size scalings at smaller dimensions than do semiconductor quantum dots. The unique discrete excitation and emission and strong Stokes and anti-Stokes Raman enhancement coupled with facile creation in aqueous solution open new opportunities for noble metal nanoclusters as biological labels, energy transfer pairs, and other light emitters in nanoscale electronics.
590 $a School code: 0078.
650 4 $a Chemistry, Physical. $3 560527
650 4 $a Engineering, Materials Science. $3 1017759
690 $a 0494
690 $a 0794
710 2 0 $a Georgia Institute of Technology. $3 696730
773 0 $t Dissertation Abstracts International $g 67-03B.
790 1 0 $a Dickson, Robert M., $e advisor
790 $a 0078
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3212325