Search results for "PLASMON RESONANCE"

Aptamer-embedded DNA origami cage for detecting (glycated) hemoglobin with a surface plasmon resonance sensor

2020

DNA origami-based cages functionalized with aptamer motifs, were used to detect hemoglobin and glycated hemoglobin. The binding between the cages and hemoglobin was monitored using a surface plasmon resonance (SPR) sensor. One DNA strand in the nano-cage was replaced with an aptamer that demonstrated a high affinity to hemoglobin (Hb) or glycated hemoglobin (gHb). Three types of the DNA nano-cages designed to fit the size and shape of hemoglobin were evaluated: one without an aptamer, one with the Hb-affinity aptamer (HA) and one with the gHb-affinity aptamer (GHA). Both DNA nano-cages embedded with HA and GHA showed significantly more stable binding with Hb and gHb by 5 and 9 times, respec…

Molecular-mediated assembly of silver nanoparticles with controlled interparticle spacing and chain length

2012

In the present work, we report on a one-pot method for the assembly of noble metal nanoparticles with tunable optical properties, assembly length and interparticle spacing. The synthetic colloidal route is based on the covalent binding among OH-terminated silver nanoparticles by means of dicarboxylic acids with a defined molecular length. As a result, the initially symmetric plasmon band of silver nanoparticles splits into two plasmonic modes when nanoparticles are assembled due to the strong near-field plasmon coupling. We noticed a very good correlation between the plasmon wavelength shift and the interparticle spacing that is represented by the universal scaling law of the surface plasmo…

Thermo-optic control of dielectric-loaded plasmonic waveguide components

2010

International audience; We report preliminary results on the development of compact (length 20%) is demonstrated with MZI-and WRR-based components, and efficient (similar to 30%) rerouting is achieved with DC switches. (C) 2010 Optical Society of America

Highly Sensitive plasmonic silver nanorods

2011

We compare the single-particle plasmonic sensitivity of silver and gold nanorods with similar resonance wavelengths by monitoring the plasmon resonance shift upon changing the environment from water to 12.5% sucrose solution. We find that silver nanoparticles have 1.2 to 2 times higher sensitivity than gold, in good agreement with simulations based on the boundary-elements-method (BEM). To exclude the effect of particle volume on sensitivity, we test gold rods with increasing particle width at a given resonance wavelength. Using the Drude-model of optical properties of metals together with the quasi-static approximation (QSA) for localized surface plasmons, we show that the dominant contrib…

Multi-frequency near-field enhancement with graphene-coated nano-disk homo-dimers.

2019

In this paper, a 3D sub-wavelength graphene-coated nano-disk dimer (GDD) is proposed for multi-frequency giant near-field enhancement. We observed that the dual-band operation originates from the excitation of hybridized localized surface plasmons on top and bottom faces of the disks along with the mutual coupling from the adjacent particle. Due to the sub-wavelength nature of the disks, the excited localized surface plasmons on the sidewalls are weak but they still can affect the dual operating bands. On the other hand, the strength and resonance frequency of the enhanced fields can be simply modulated by tuning the relative distances of 2D graphene disks on top and bottom faces. Adjustabl…

Acousto-plasmonic coupling in engineered metal nanocomposites

2010

This work shows the production of self-assembled elongated nano-objects embedded in an oxide host oriented perpendicular to the substrate and their acousto-plasmonic dynamics. Electromagnetic “hot spots” are created that activate anomalous Raman vibrational modes.

DEVELOPMENT AND NEAR-FIELD CHARACTERIZATION OF SURFACE PLASMON WAVEGUIDES

2007

Direct observation of localized surface plasmon coupling

1999

We report on the direct observation of localized surface plasmon coupling using a photon scanning tunneling microscope. The surface plasmons are excited in gold nanostructures tailored by electron beam lithography. Electromagnetic energy transfer from a resonantly excited nanoparticle to a nanowire, which is not directly excited by the incident light is observed. Our experimental results appear to be in good agreement with theoretical computations based on Green's dyadic technique.

Mapping surface plasmon propagation by collection-mode near-field microscopy

2011

Surface plasmon propagation along striped Gold structures has been investigated by collection-mode near-field microscopy, leading to map the field intensity at the structure surface and to assess the system behavior at the nanoscale.

Chapter 3 Surface Plasmon Optics for the Characterization of Biofunctional Architectures

2007

Publisher Summary This chapter describes a wide variety of work employing surface plasmon resonance (SPR), surface plasmon field-enhanced fluorescence spectroscopy (SPFS), and surface plasmon field-enhanced diffraction spectroscopy (SPDS) analysis, specifically for investigations relevant to biofunctional, bio-affinity aspects. The SPR has shown already its impact on interfacial analysis. The combination of these three methods has the potential to generate more information and reveal details of biofunctional interfaces. The versatility of the SPR technique is shown by a vast amount of publications in the past decades; the method has matured into a well-accepted analytical tool for the chara…