| 1. |
- Fang, Yurui, et al.
(författare)
-
Branched Silver Nanowires as Controllable Plasmon Routers
- 2010
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 10:5, s. 1950-1954
-
Tidskriftsartikel (refereegranskat)abstract
- Using polarization dependent scattering spectroscopy, we investigate plasmon propagation on branched silver nanowires. By controlling the polarization of the incident laser light, the wire plasmons can be routed into different wire branches and result in light emission from the corresponding wire ends. This routing behavior is found to be strongly dependent on the wavelength of light. Thus for certain incident polarizations, light of different wavelength will be routed into different branches. The branched nanowire can thus serve as a controllable router and multiplexer in integrated plasmonic circuits.
|
|
| 2. |
|
|
| 3. |
- Li, Zhipeng, et al.
(författare)
-
Effect of a proximal substrate on plasmon propagation in silver nanowires
- 2010
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 82:24
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate how the properties of a nearby substrate modify the excitation and propagation of plasmons in subwavelength silver wires. With decreasing nanowire-substrate separation, the in-coupling efficiency shows strongly oscillatory behavior due to coherent interference. The plasmon damping increases with decreasing separation due to an increased coupling of the nanowire plasmons to the photonic modes of the substrate.
|
|
| 4. |
- Neumann, Oara, et al.
(författare)
-
Direct optical detection of aptamer conformational changes induced by target molecules
- 2009
-
Ingår i: Analytical chemistry. - : ACS Publications. - 1520-6882 .- 0003-2700. ; 81:24, s. 10002-6
-
Tidskriftsartikel (refereegranskat)abstract
- Aptamers are single-stranded DNA/RNA oligomers that fold into three-dimensional conformations in the presence of specific molecular targets. Surface-enhanced Raman spectroscopy (SERS) of thiol-bound DNA aptamer self-assembled monolayers on Au nanoshell surfaces provides a direct, label-free detection method for the interaction of DNA aptamers with target molecules. A spectral cross-correlation function, Gamma, is shown to be a useful metric to quantify complex changes in the SERS spectra resulting from conformational changes in the aptamer induced by target analytes. While the pristine, unexposed anti-PDGF (PDGF = platelet-derived growth factor) aptamer yields highly reproducible spectra with Gamma = 0.91 +/- 0.01, following incubation with PDGF, the reproducibility of the SERS spectra is dramatically reduced, yielding Gamma = 0.67 +/- 0.02. This approach also allows us to discriminate the response of a cocaine aptamer to its target from its weaker response to nonspecific analyte molecules.
|
|
| 5. |
- Wei, Hong, et al.
(författare)
-
Quantum Dot-Based Local Field Imaging Reveals Plasmon-Based Interferometric Logic in Silver Nanowire Networks
- 2011
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 11:2, s. 471-475
-
Tidskriftsartikel (refereegranskat)abstract
- We show that the local electric field distribution of propagating plasmons along silver nanowires can be imaged by coating the nanowires with a layer of quantum dots, held off the surface of the nanowire by a nanoscale dielectric spacer layer. In simple networks of silver nanowires with two optical inputs, control of the optical polarization and phase of the input fields directs the guided waves to a specific nanowire output. The QD-luminescent images of these structures reveal that a complete family of phase-dependent, interferometric logic functions can be performed on these simple networks. These results show the potential for plasmonic waveguides to support compact interferometric logic operations.
|
|
| 6. |
- Zhang, Dongmao, et al.
(författare)
-
Gold Nanoparticles Can Induce the Formation of Protein-based Aggregates at Physiological pH
- 2009
-
Ingår i: NANO Letters. - : ACS Publications. - 1530-6984 .- 1530-6992. ; 9:2, s. 666-71
-
Tidskriftsartikel (refereegranskat)abstract
- Protein-nanoparticle interactions are of central importance in the biomedical applications of nanoparticles, as well as in the growing biosafety concerns of nanomaterials. We observe that gold nanoparticles initiate protein aggregation at physiological pH, resulting in the formation of extended, amorphous protein-nanoparticle assemblies, accompanied by large protein aggregates without embedded nanoparticles. Proteins at the Au nanoparticle surface are observed to be partially unfolded; these nanoparticle-induced misfolded proteins likely catalyze the observed aggregate formation and growth.
|
|
| 7. |
- Zhang, Shunping, et al.
(författare)
-
Chiral Surface Plasmon Polaritons on Metallic Nanowires
- 2011
-
Ingår i: Physical Review Letters. - 1079-7114. ; 107:9
-
Tidskriftsartikel (refereegranskat)abstract
- Chiral surface plasmon polaritons (SPPs) can be generated by linearly polarized light incident at the end of a nanowire, exciting a coherent superposition of three specific nanowire waveguide modes. Images of chiral SPPs on individual nanowires obtained from quantum dot fluorescence excited by the SPP evanescent field reveal the chirality predicted in our theoretical model. The handedness and spatial extent of the helical periods of the chiral SPPs depend on the input polarization angle and nanowire diameter as well as the dielectric environment. Chirality is preserved in the free-space output wave, making a metallic nanowire a broad bandwidth subwavelength source of circular polarized photons.
|
|
