Synthesis and Optical Properties of “Branched” Gold Nanocrystals

Abstract

We report the synthesis of new "branched" gold nanocrystals in high yield (over 90%) via a wet-chemical route. The branched nanocrystals exhibit a shape-dependent plasmon resonance that is red-shifted by 130−180 nm from the spherical particle wavelength. Discrete dipole approximation (DDA) calculations qualitatively replicate the observed optical extinction spectra of the nanocrystals, indicating that the surface plasmon resonance is mainly determined by in-plane dipole excitation associated with the sharp tips.

Biomedical Applications of Plasmon Resonant Metal Nanoparticles

“…Silver nanoparticles can be synthesized with controlled shape and optical properties guided by optical illumination [18]. More complex architectures have also been described, including gold nanocages [19][20][21], elongated core-shell geometries [22] and gold nanostars [23][24][25][26][27][28].…”

Symmetry breaking in individual plasmonic nanoparticles

“…The optical properties of a metallic nanoparticle are determined by its plasmon resonances, which are strongly dependent on particle geometry. The structural tunability of plasmon resonances has been one of the reasons for the growing interest in a rapidly expanding array of nanoparticle geometries, such as nanorods (1,2), nanorings (3), nanocubes (4,5), triangular nanoprisms (6)(7)(8), nanoshells (9), and branched nanocrystals (10,11). The resonant excitation of plasmons can lead to large local enhancements of the incident electromagnetic field at the nanoparticle surface, resulting in dramatically large enhancements of the cross section for nonlinear optical spectroscopies such as surface-enhanced Raman scattering (12)(13)(14)(15)(16).…”

Nanoplasmonics and its Applied Devices

“…Scientist gained significant control both the over size [7] and surfaces [8][9][10][11][12] for nanoparticles. They have demonstrated that anisotropy in nanostructure like triangular prisms [13][14][15][16][17][18], nanoscale rods [19][20][21][22][23][24][25][26], nanoshells [27][28][29][30][31], multipods [32][33][34], disks [35][36][37][38][39] and cubes [40][41][42] shows better performance over solid spheres. …”