Xiaoge Hu

Well-ordered end-to-end linkage of gold nanorods

In this study, it is found that as-prepared gold nanorods can be linked to each other in an end-to-end way by using cysteine as a molecular bridge. Both transmission electron microscopy and UV-visible optical spectroscopy demonstrated the uniaxial assembly of the gold nanorods. The controlled addition of cysteine into the gold nanorod solution resulted in their preferential binding to the two ends of the gold nanorods. As a result, end-to-end assembly was achieved through cooperative hydrogen bonding of bound cysteine molecules. The as-synthesized end-to-end linked assembly of gold nanorods is well ordered and on a large scale. For comparison, three other neutral amino acids, glycine, alanine and valine, were also investigated but the orderliness of their assembly is not as good as that in the case of cysteine.

A general route to transform normal hydrophilic cloths into superhydrophobic surfaces

Herein, we describe a simple and inexpensive method for forming superhydrophobic cloths with the highest water contact angle of close to 180 degrees , in which normal commercial cloths serving as pristine materials are modified with suitable gold micro/nanostructures.

A Renewable SERS Substrate Prepared by Cyclic Depositing and Stripping of Silver Shells on Gold Nanoparticle Microtubes

State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China We also examine the influence of the amount of reducing agent and the diameter of nanoparticles on SERS spectra. When the concentration of ascorbic acid was decreased from 7.6 mM to 3.6 mM, the SERS spectra collected from the silver/gold microtubes contained dominant a1 vibrational modes even with a deposition time for silver atoms of only 3 min, indicating that an uniform and complete silver shell on gold nanoparticles can be prepared easily by decreasing in the deposition rate of the silver atoms. As the deposition time of silver shells increases, the SERS intensity of 4-ATP also increases (Figure S1 shown in supporting information), which can be due to an increased nanoparticles diameter.

Surface-enhanced Raman scattering from surfactant-free 3D gold nanowire networks substrates.

A useful method for the fabrication of three-dimensional gold nanowire networks based on the chemical reduction of HAuCl4 with trisodium citrate was presented. The coverage of the 3D gold nanowire networks was tunable by altering precursor concentration. The as-prepared 3D gold nanowire networks could be used as surface-enhanced Raman scattering (SERS) substrates and examined by 4-aminothiophenol (4-ATP) as a probe molecules. Since the proposed strategy is simple, cost-effective and reproducible for the mass production of network-like gold films irrespective of the kinds of the underlying substrates, it is expected to play an important role in the development of surface plasmon-based analytical devices.

Construction of metal nanoparticle/multiwalled carbon nanotube hybrid nanostructures providing the most accessible reaction sites

Functionalized multiwalled carbon nanotubes (MWNTs) were selected as cross-linkers to construct three-dimensional (3D) porous nanoparticle/MWNT hybrid nanostructures by “bottom-up” self-assembly. The resultant 3D hybrid nanostructure was different from that of metal nanoparticle multilayer assemblies prepared by traditional routes using small molecules or polymers as cross-linkers. The rigidity of the MWNTs resulted in only partial coverage of the nanoparticle surfaces between the linkers during the growth of multilayer film, providing more accessible surfaces to allow target molecules to adsorb on to and react with. HRP was used as a simple model to study the porosity of this assembly.