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Surface plasmons

Svitlana G Ilchenko, Ruslan A Lymarenko, Victor B Taranenko
We propose using a specially designed metal-multilayer-dielectric structure deposited on glass substrate to enhance the evanescent field and improve the sensitivity of the surface plasmon resonance sensor. The proposed structure supports both hybrid plasmonic transverse magnetic modes and conventional waveguide transverse electric modes. We show numerically the significant enhancement of the evanescent field and improvement of the sensitivity for the waveguide transverse electric mode.
December 2017: Nanoscale Research Letters
Torsten Linker, Prashant Pavashe, Werner Fudickar
Carbohydrates carrying thiol groups at the C-2 position have been attached to gold nanoparticles (AuNP) with stereocenters in close proximity to the surface for the first time. Their configurations can be clearly distinguished by the tendency of particle aggregation. AuNP surface plasmon resonance (SPR), x-ray photoelectron spectroscopy (XPS), and IR spectroscopy indicate that the thiocarbohydrates replace citrate molecules at different rates causing aggregation and eventually precipitation. A quantitative formulation of this aggregation process shows that reactivities can vary by several magnitudes...
April 26, 2017: Chemistry: a European Journal
Xiaolu Meng, Zhuo Mao, Xin Li, Dandan Zhong, Min Li, Yingli Jia, Jing Wei, Baoxue Yang, Hong Zhou
Baicalein, a natural flavonoid, is structurally advantageous for binding to xanthine oxidoreductase. In our study, molecular docking analysis and Surface Plasmon Resonance revealed a direct interaction between baicalein and xanthine oxidoreductase. Moreover, 50 mg/kg/d baicalein treatment significantly suppressed the viability of xanthine oxidoreductase in hyperuricemia mouse model. The data showed that baicalein remarkably prevented renal dysfunction, ameliorated kidney fibrosis, alleviated epithelial-mesenchymal transition and oxidative stress in hyperuricemia mice...
April 7, 2017: Oncotarget
Dongxu Han, Zongbi Bao, Huabin Xing, Yiwen Yang, Qilong Ren, Zhiguo Zhang
The Suzuki-Miyaura reaction is one of the most popular and efficient routes for the formation of carbon-carbon bonds in both laboratorial and industrial synthetic processes. Here, we report for the first time that a Au-Pd/TiO2 catalyst could be utilized efficiently for Suzuki-Miyaura reactions at ambient conditions under visible light with high activity and reusability. Mechanistic investigation by means of experimental methods revealed that through the strong local surface plasma resonance of Au under the visible light, the hot electrons of Au could be injected into Pd in the bimetallic nanoparticles, thus facilitating activation of the aryl halides...
April 26, 2017: Nanoscale
Benedetta Bertolotti, Ieva Sutkeviciute, Martino Ambrosini, Renato Ribeiro-Viana, Javier Rojo, Franck Fieschi, Hana Dvořáková, Martina Kašáková, Kamil Parkan, Martina Hlaváčková, Kateřina Nováková, Jitka Moravcová
The C-type lectin DC-SIGN expressed on immature dendritic cells is a promising target for antiviral drug development. Previously, we have demonstrated that mono- and divalent C-glycosides based on d-manno and l-fuco configurations are promising DC-SIGN ligands. Here, we described the convergent synthesis of C-glycoside dendrimers decorated with 4, 6, 9, and 12 α-l-fucopyranosyl units and with 9 and 12 α-d-mannopyranosyl units. Their affinity against DC-SIGN was assessed by surface plasmon resonance (SPR) assays...
April 26, 2017: Organic & Biomolecular Chemistry
Quanlong Yang, Xueqian Zhang, Shaoxian Li, Quan Xu, Ranjan Singh, Yongmin Liu, Yanfeng Li, Sergey S Kruk, Jianqiang Gu, Jiaguang Han, Weili Zhang
Excitation and manipulation of surface plasmons (SPs) are essential in developing cutting-edge plasmonic devices for medical diagnostics, biochemical spectroscopy and communications. The most common approach involves designing an array of periodic slits or grating apertures that enables coupling of the incident light to the SP modes. In recent years, plasmonic resonances, including extraordinary optical transmission through periodic arrays, quasicrystals and random aperture arrays, have been investigated in the free space...
December 23, 2016: Scientific Reports
Ryan T VanderLinden, Casey W Hemmis, Tingting Yao, Howard Robinson, Christopher P Hill
The 26S proteasome is a large cellular assembly that mediates the selective degradation of proteins in the nucleus and cytosol and is an established target for anti-cancer therapeutics. Protein substrates are typically targeted to the proteasome through modification with a polyubiquitin chain, which can be recognized by several proteasome-associated ubiquitin receptors. One of these receptors, RPN13/ADRM1, is recruited to the proteasome through direct interaction with the large scaffolding protein RPN2 within the 19S regulatory particle...
April 25, 2017: Journal of Biological Chemistry
Marlia Morsin, Muhamad Mat Salleh, Akrajas Ali Umar, Mohd Zainizan Sahdan
Localized surface plasmon resonance (LSPR) properties of metallic nanostructures, such as gold, are very sensitive to the dielectric environment of the material, which can simply be adjusted by changing its shape and size through modification of the synthesizing process. Thus, these unique properties are very promising, particularly for the detection of various types of chemicals, for example boric acid which is a non-permitted preservative employed in food preparations. For the sensing material, gold (Au) nanoplates with a variety of shapes, i...
April 25, 2017: Sensors
Shiwei Miao, Panpan Xie, Mao Zou, Li Fan, Xuping Liu, Yan Zhou, Liang Zhao, Ding Ding, Haibin Wang, Wen-Song Tan
Charge variants, especially acidic charge variants, of recombinant monoclonal antibodies are the major critical quality attributes in the biotechnology industry due to their potential influence on stability and biological activity. The chemical properties of the acidic charge variants have been challenging to fully characterize, and it is critical for process development and optimization. To completely understand the multiple sources of acidic charge variants, the major charge forms of an IgG1 monoclonal antibody were firstly isolated and then analyzed by a battery of characterization tools...
April 24, 2017: Applied Microbiology and Biotechnology
Hua-Zhou Chen, Jia-Qi Hu, Suo Wang, Bo Li, Xing-Yuan Wang, Yi-Lun Wang, Lun Dai, Ren-Min Ma
Spasers are a new class of laser devices with cavity sizes free from optical diffraction limit. They are an emergent tool for various applications, including biochemical sensing, superresolution imaging, and on-chip optical communication. According to its original definition, a spaser is a coherent surface plasmon amplifier that does not necessarily generate a radiative photon output. However, to date, spasers have only been studied with scattered photons, and their intrinsic surface plasmon emission is a "dark" emission that is yet to be revealed because of its evanescent nature...
April 2017: Science Advances
Mingxia Song, Jean Dellinger, Olivier Demichel, Mickaël Buret, Gérard Colas Des Francs, Douguo Zhang, Erik Dujardin, Alexandre Bouhelier
Surface plasmon modes propagating in metal nanowires are conveniently excited by focusing a laser beam on one extremity of the nanowire. We find that the precise positioning of the nanowire inside the focal region drastically influences the excitation efficiency of the different SPP modes sustained by the plasmonic waveguide. We demonstrate a spatially selective excitation of bound and leaky surface plasmon modes with excitation maps that strongly depend on the orientation of the incident linear polarization...
April 17, 2017: Optics Express
Seojun Lee, Hyungchae Kim, Jongcheon Lee, Changsoon Kim
We investigate scattering of surface plasmon polaritons (SPPs) at a planar metal-dielectric interface by a dielectric nanocube embedded in the metal layer using finite element method-based simulations. The scattering characteristics of the embedded nanocube, such as the scattering and absorption cross sections, far-field scattering patterns, reflectance, and transmittance, are calculated as functions of the wavelength of the incident SPP waves in the visible range. The main features of the characteristics are explained in connection with the excitation of plasmonic eigenmodes of the embedded nanocube...
April 17, 2017: Optics Express
Abdul Khaleque, Evgeny G Mironov, Jonas H Osório, Ziyuan Li, Cristiano M B Cordeiro, Liming Liu, Marcos A R Franco, Jong-Leng Liow, Haroldo T Hattori
In this article, a new and flexible approach to control the electric field enhancement of bow-tie nano-antennas by integrating them on the lateral of a tapered optical fiber is proposed. The device is driven by a Q-switched laser and the performance of a fabricated nano-antenna in a quartz slide is tested by a Surface Enhanced Raman Scattering (SERS) experiment. A refractive index sensing experiment is also performed and a sensitivity of (240 ± 30) nm/RIU is found in the 1.33-1.35 index range.
April 17, 2017: Optics Express
Mengdi Lu, Wei Peng, Qiang Liu, Yun Liu, Lixia Li, Yuzhang Liang, Jean-Francois Masson
We present a novel multilayer-coated surface plasmon resonance sensor for dual refractive index range measurements based on a capillary structure. The sensing elements include an internally coated Ag layer and an externally coated bilayer of Au with an overlayer of thin indium tin oxide (ITO). The internal Ag layer was sensitive to higher refractive index (RI) medium while the external Au/ITO layer was sensitive to lower refractive index medium. We evaluated the sensor performance by measuring RI changes in two channels, RI sensitivities were -1951 nm/RIU and 2496 nm/RIU, respectively...
April 17, 2017: Optics Express
Yi Zhao, Ceji Fu
In this paper, we present a one-dimensional periodic microstructure for multiband selective absorbers of thermal radiation. The microstructure is made of Ag/SiO<sub>2</sub>/Ag core/shell coaxial cylinders horizontally lying on top of a SiO<sub>2</sub> dielectric spacer and an opaque silver substrate. The spectral-directional absorptivity of the proposed structure was numerically investigated with the finite element based Comsol Multiphysics software. Multiband selective absorption in the wavenumber range from 2500 to 20000 cm<sup>-1</sup> for TM-wave incidence was obtained...
April 17, 2017: Optics Express
Takahide Sakaidani, Ryo Kobayashi, Naoto Namekata, Go Fujii, Daiji Fukuda, Shuichiro Inoue
High-order dispersion of long-range surface-plasmon-polariton waveguides (LR-SPP-WGs) have been investigated using a two-photon interferometer. Since linear and even-ordered dispersions in two-photon interferometry are cancelled out by a nonlocal quantum correlation, odd-ordered dispersions of millimeter-long LR-SPP-WGs are revealed. Even under the highly dispersive condition, the indistinguishability between two photons emerged from LR-SPP-WGs was well preserved. In addition, we demonstrated a strong polarization-selection by the LR-SPP-WGs that leads to the polarization-stable and high-fidelity quantum interference...
April 17, 2017: Optics Express
Xin-Hao Li, Jeffrey B Chou, Wei Lek Kwan, Asma M Elsharif, Sang-Gook Kim
We recently reported that an Au/TiO<sub>2</sub> photonic crystal device for photochemical energy conversion showed a sub-bandgap photoresponse centered at the surface plasmon polariton (SPP) resonant wavelength of this device. Here we developed a theoretical modeling of the internal photoemission in this device by incorporating the effects of anisotropic hot electron momentum distribution caused by SPP. The influences of interband and intraband transition, anisotropic momentum distribution of hot electrons by SPP are integrated to model the internal quantum efficiency (IQE) of this device...
April 17, 2017: Optics Express
Cyntia F Montenegro, Bruna C Casali, Rafael L B Lino, Bianca C Pachane, Patty K Santos, Alan R Horwitz, Heloisa S Selistre-de-Araujo, Marcelo L Lamers
The connective tissue formed by extracellular matrix (ECM) rich in fibronectin and collagen consists a barrier that cancer cells have to overpass to reach blood vessels and then a metastatic site. Cell adhesion to fibronectin is mediated by αvβ3 and α5β1 integrins through an RGD motif present in this ECM protein, thus making these receptors key targets for cell migration studies. Here we investigated the effect of an RGD disintegrin, DisBa-01, on the migration of human fibroblasts (BJ) and oral squamous cancer cells (OSCC, SCC25) on a fibronectin-rich environment...
2017: PloS One
Keren Jiang, Yinan Wang, Garima Thakur, Yohei Kotsuchibashi, Selvaraj Naicker, Ravin Narain, Thomas Thundat
A conjugated polymer interface consisting of an oxaborole containing polymer and a glycopolymer was used for achieving very high selectivity in dopamine (DA) detection. The optimum binding affinity between the polymers promotes the selectivity to DA through a displacement mechanism while remaining unaffected by other structurally related analogs and saccharide derivatives. Real-time detection of DA with very high selectivity and sensitivity has been demonstrated by immobilizing the polymer conjugates on surface plasmon resonance (SPR) and microcantilever (MCL) sensor platforms...
April 24, 2017: ACS Applied Materials & Interfaces
Maija Vuoriluoto, Hannes Orelma, Meri Johanna Lundahl, Maryam Borghei, Orlando J Rojas
We demonstrate benzophenone (BP) conjugation via amine-reactive esters onto oxidized cellulosic fibers that were used as precursors, after microfluidization, of photo-active cellulose nanofibrils (CNF). From these fibrils, cellulose I filaments were synthesized by hydrogel spinning in an anti-solvent followed by fast bi-radical UV crosslinking. As a result, the BP-CNF filaments developed a wet tensile strength of up to ~105 MPa (a remarkable retention of ~80% of the dry strength). Thus, the principal limitation of these emerging materials was resolved (< 0...
April 24, 2017: Biomacromolecules
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