Skip to main content Accessibility help

Composition, particle size, and near-infrared irradiation effects on optical properties of Au–Au2S nanoparticles

  • Mei Chee Tan (a1), Jackie Y. Ying (a2) and Gan Moog Chow (a3)


Near-infrared (NIR)-absorbing nanoparticles synthesized by the reduction of tetrachloroauric acid (HAuCl4) using sodium sulfide (Na2S) exhibited absorption bands at ∼530 nm and at the NIR region of 650−1100 nm. A detailed study on the structure and microstructure of as-synthesized nanoparticles was reported previously. The as-synthesized nanoparticles were found to consist of amorphous AuxS (x = ∼2), mostly well mixed within crystalline Au. In this work, the optical properties were tailored by varying the precursor molar ratios of HAuCl4 and Na2S. In addition, a detailed study of composition and particle-size effects on the optical properties was discussed. The change of polarizability by the introduction of S in the form of AuxS (x = ∼2) had a significant effect on NIR absorption. Also, it was found in this work that exposure of these particles to NIR irradiation using a Nd:YAG laser resulted in loss of the NIR absorption band. Thermal effects generated during NIR irradiation had led to microstructural changes that modified the optical properties of particles.


Corresponding author

a)Address all correspondence to this author. e-mail:


Hide All
1Brannon-Peppas, L.Blanchette, J.O.: Nanoparticle and targeted systems for cancer therapy. Adv. Drug Delivery Rev. 56, 1649 2004
2Kost, J.Langer, R.: Responsive polymeric delivery systems. Adv. Drug Delivery Rev. 46, 125 2001
3Frangioni, J.V.: In vivo near-infrared fluorescence imaging. Curr. Opin. Chem. Biol. 7, 626 2003
4Weissleder, R.: A clearer vision for in vivo imaging. Nat. Biotechnol. 19, 316 2001
5Ren, L.Chow, G.M.: Synthesis of NIR-sensitive Au-Au2S nanocolloids for drug delivery. Mater. Sci. Eng., C 23, 113 2003
6Chow, G.M., Tan, M.C., Ren, L.Ying, J.Y.: NIR-sensitive nanoparticles, U.S. Patent (application pending) No. 2006099146 (May 11, 2006)
7Oldenburg, S.J., Averitt, R.D., Westcott, S.L.Halas, N.J.: Nanoengineering of optical resonances. Chem. Phys. Lett. 288, 243 1998
8Loo, C., Lowery, A., Halas, N., West, J.Drezek, R.: Immunotargeted nanoshells for integrated cancer imaging and therapy. Nano Lett. 5, 709 2005
9Hirsch, L.R., Stafford, R.J., Bankson, J.A., Sershen, S.R., Rivera, B., Price, R.E., Hazle, J.D., Halas, N.J.West, J.L.: Nanoshell-mediated near-infrared thermal therapy of tumors under magnetic resonance guidance. Proc. Natl. Acad. Sci. U.S.A. 100, 13549 2003
10Sershen, S.West, J.: Implantable, polymeric systems for modulated drug delivery. Adv. Drug. Delivery Rev. 54, 1225 2002
11Hirsch, L.R., Jackson, J.B., Lee, A., Halas, N.J.West, J.: A whole blood immunoassay using gold nanoshells. Anal. Chem. 75, 2377 2003
12Zhou, H.S., Honma, I.Komiyama, H.: Controlled synthesis and quantum-size effect in gold-coated nanoparticles. Phys. Rev. B: Condens. Matter 50, 12052 1994
13Averitt, R.D., Sarkar, D.Halas, N.J.: Plasmon resonance shifts of Au-coated Au2S nanoshells. Phys. Rev. Lett. 78, 4217 1997
14Tan, M.C., Ying, J.Y.Chow, G.M.: Structure and microstructure of near infrared-absorbing Au-Au2S nanoparticles. J. Mater. Res. 22, 2531 2007
15Kamat, P.V.: Photophysical, photochemical and photocatalytic aspects of metal nanoparticles. J. Phys. Chem. B 106, 7729 2002
16Link, S., Burda, C., Mohamed, M.B., Nikoobakht, B.El-Sayed, M.A.: Laser photothermal melting and fragmentation of gold nanorods: Energy and laser pulse width dependence. J. Phys. Chem. A 103, 1165 1999
17Link, S.El-Sayed, M.A.: Size and temperature dependence of the plasmon absorption of colloidal gold nanoparticles. J. Phys. Chem. B 103, 4212 1999
18Link, S.El-Sayed, M.A.: Shape and size dependence of radiative, non-radiative and photothermal properties of gold nanocrystals. Int. Rev. Phys. Chem. 19, 409 2000
19Kittel, C.Introduction to Solid State Physics 8th ed.John Wiley & Sons Hoboken, NJ 2005
20Kreibig, U.Vollmer, M.: Optical Properties of Metal Clusters Springer Berlin 1995
21Fox, M.: Optical Properties of Solids Oxford University Press New York 2000
22Voisin, C., Fatti, N.D., Christofilos, D.Vallée, F.: Ultrafast electron dynamics and optical non linearities in metal nanoparticles. J. Phys. Chem. B 105, 2264 2001
23Pinchuk, A., von Plessen, G.Kreibig, U.: Influence of interband electronic transitions on the optical absorption in metallic nanoparticles. J. Phys. D: Appl. Phys. 37, 3313 2004
24Licht, S.: Aqueous solubilities, solubility products and standard oxidation-reduction potentials of the metal sulfides. J. Electrochem. Soc. 135, 2971 1988
25Turkevich, J., Stevenson, P.C.Hillier, J.: The nucleation and growth processes in the synthesis of colloidal gold. Discuss. Faraday Soc. 11, 55 1951
26Stokes, R.J.Evans, D.F.: Fundamentals of Interfacial Engineering Wiley-VCH New York 1997
27Davey, R.J.Garside, J.: From Molecules to Crystallizers Oxford University Press Oxford, UK 2000
28Klug, H.P.Alexander, L.E.: X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials 2nd Ed.John Wiley & Sons New York 1974
29Koningsberger, D.C.Prins, R.: X-ray absorption: Principles, Applications, Techniques of EXAFS, SEXAFS and XANES John Wiley & Sons New York 1988
30Gurman, S.J.: Interpretation of EXAFS data. J. Synchrotron Rad. 2, 56 1995
31Stern, E.A.: Theory of the extended x-ray absorption fine structure. Phys. Rev. B: Solid State 10, 3027 1974
32Petiau, J., Sainctavit, P.Calas, G.: X-ray absorption spectra and electronic structure of chalcopyrite. Mater. Sci. Eng., B 1, 237 1988
33Watts, J.F.Wolstenholme, J.: An Introduction to Surface Analysis by XPS and AES John Wiley & Sons New York 2003
34Lide, D.R.CRC Handbook of Chemistry and Physics 85th ed.CRC Press Cleveland, OH 2004
35Link, S., Wang, Z.L.El-Sayed, M.A.: Alloy formation of gold-silver nanoparticles and the dependence of the plasmon absorption on their composition. J. Phys. Chem. B 103, 3529 1999
36van Gemert, M.J.C.Welch, A.J.: Time constants in thermal laser medicine. Lasers Surg. Med. 9, 405 1989
37Hu, M.Hartland, G.V.: Heat dissipation for Au particles in aqueous solution: Relaxation time versus size. J. Phys. Chem. B 106, 7029 2002
38Cleveland, C.L., Luedtke, W.D.Landman, U.: Melting of gold clusters. Phys. Rev. B: Condens. Matter 60, 5065 1999
39Kan, C., Zhu, X.Wang, G.: Single-crystalline gold microplates: Synthesis, characterization, and thermal stability. J. Phys. Chem. B 110, 4651 2006
40Gillet, M.: Structure of small metallic particles. Surf. Sci. 67, 139 1977
41Uyeda, N., Nishino, M.Suito, E.: Nucleus interactions and fine structures of colloidal gold particles. J. Colloid Interface Sci. 43, 264 1972
42Komoda, T.: Study on the structure of evaporated gold particles by means of a high resolution electron microscope. Jpn. J. Appl. Phys. 7, 27 1968
43Jena, P., Khanna, S.N.Rao, B.K.: Physics and Chemistry of Finite Systems: From Clusters to Crystals Vol. 1 Kluwer Academic Dordrecht, The Netherlands 1992 93
44Vogel, W., Bradley, J., Vollmer, O.Abraham, I.: Transition from five-fold symmetric to twinned fcc gold particles by thermally induced growth. J. Phys. Chem. B 102, 10853 1998
45Wynblatt, P.Ku, R.C.: Surface energy and solute strain energy effects in surface segregation. Surf. Sci. 65, 511 1977
46Liu, F.Metiu, H.: Dynamics of phase separation of crystal surfaces. Phys. Rev. B: Condens. Matter 48, 5808 1993
47Osborn, J.A.: Demagnetizing factors of the general ellipsoid. Phys. Rev. 67, 351 1945


Composition, particle size, and near-infrared irradiation effects on optical properties of Au–Au2S nanoparticles

  • Mei Chee Tan (a1), Jackie Y. Ying (a2) and Gan Moog Chow (a3)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed