Dong-Feng Zhang

Publications (2)3.29 Total impact

• Article: Self-assembly of gold nanoparticles into chain-like structures and their optical properties

  Dong-Feng Zhang, Qian Zhang, Li-Ya Niu, Li Jiang, Peng-Gang Yin, Lin Guo
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  ABSTRACT: Au nanoparticles with diameters of ca. 15nm were synthesized according to the well-developed citrate reduction method. It was found that the nanoparticles tended to attach and fuse into each other to form chain-like structures with the removal of the stabilizing agents. UV–Vis absorption and HRTEM characterizations provided solid evidence for the fused features. On the basis of the HRTEM observations, we believed the decreased surface energy as well as the dipole–dipole interaction is responsible for the formation of the chain-like structures. SERS activity investigation indicated that the intensities of the b2-type bands have close relation with the concentration of the probing molecules, which further confirmed the chemical effect character of the b2-type scatterings. KeywordsGold nanoparticle–Self-assembly–Chain-like–SERS–SPR–Surface energy
  Journal of Nanoparticle Research 05/2012; 13(9):3923-3928. · 3.29 Impact Factor
• Article: Branched Gold Nanochains Facilitated by Polyvinylpyrrolidone and their SERS Effects on p-Aminothiophenol

  Dong-Feng Zhang, Li-Ya Niu, Li Jiang, Peng-Gang Yin, Ling-Dong Sun, Hua Zhang, Rui Zhang, Lin Guo, Chun-Hua Yan
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  ABSTRACT: Stable gold nanochains with branched features were fabricated at room temperature with the assistance of polyvinylpyrrolidone (PVP). An attachment and fusion process was believed to responsible for the formation of the chain-like structure. During the process, PVP acted both as a structure-directing agent and as a stabilizer to inhibit continuous size increase. UV−vis−NIR study revealed that the unique structure shifted the longitudinal surface plasma resonant band (LSPR) to as far as 1457 nm, which may endow the product with new applications. The surface-enhanced Raman scattering activity was investigated with p-aminothiophenol as probe molecule. The enhancement factor (EF) of the products deposited as film on the Si substrate was estimated to be (1.03 ± 0.74) × l06 for the a1-type band, while it was (1.32 ± 0.15) × l07 for b2-type band. The enhancement of a1 modes was attributed to the electromagnetic mechanism, whereas the additional EF for the b2 mode is presumed to contribute from the chemical effect.
  09/2008;