Synthesis and characterization of gold nanodogbones by the seeded mediated growth method.

Novel gold nanodogbones (GDBs) are successfully fabricated using a simple seeded mediated growth (SMG) method. The shapes of GDBs depend on the amount of added vitamin C solvent. The amount of vitamin C solvent was varied from 10 to 40 µl to investigate the influence of vitamin C solvent on the GDBs. It is found that the aspect ratios (R) of GDBs were in the range from 2.34 to 1.46, and the UV-vis absorption measurement revealed a pronounced blueshift on the longitudinal surface plasmon resonance (SPR) band from 713 to 676 nm. The GDBs were determined by x-ray diffraction (XRD) to be single-crystalline with a face-centered cubic (fcc) structure. The lattice constant calculated from this selected-area electron diffraction (SAED) pattern is 4.068 Å.

Electrochemical formation of crooked gold nanorods and gold networked structures by the additive organic solvent.

Crooked gold nanorods (CGNRs) and gold network structures are fabricated using a simple electrochemical approach. The growth solution is prepared by surfactant solution as micelle templates with isopropanol (IPA) solvent. The shape of crooked nanorods and networks structure depend on the amount of added IPA solvent. To investigate the influence of isopropanol solvent on the CGNRs, the amount of IPA was varied in the range from 0.05 to 0.2 mL. It was found that the aspect ratios (gamma) of CGNRs were in the range from 1.06 to 1.46, and the UV-vis absorption measurement revealed a pronounced red-shift of the surface plasmon resonance (SPR) band from 532 to 560 nm. High-resolution transmission electron microscopy (HRTEM) showed that the formation of crooked nanorod structure was induced by aggregation of many small gold nuclei between the several large gold nanoparticles during growth, causing the small gold nuclei to link the gold nanoparticles. The CGNRs have a polycrystalline structure via the analysis from selected-area electron diffraction (SAED).

Synthesis of the gold nanodumbbells by electrochemical method.

The gold nanoparticles with novel dumbbells-like structures have been successfully fabricated by an electrochemical method using micelle template formed by two surfactants, the primary surfactant being cetyltrimethylammonium bromide (CTABr) and the co-surfactant being tetradecyltrimethylammonium bromide (TTABr). The shape of gold nanoparticles can be modified to form dumbbell structure by addition of acetone solvent during the electrolysis. The gold nanodumbbells have been determined to be single-crystalline with a face-centered cubic (FCC) structure by X-ray diffraction (XRD) analysis. The lattice constant calculated from this selected-area electron diffraction (SAED) pattern is 4.068 A. Transmission electronic microscopy (TEM) suggests that shape of gold nanodumbbell is fatter in two ends and thinner in the middle section to compare with the normal nanorod shape. These gold nanodumbbells exhibit aspect ratio (gamma) of around 3.