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Zhijun Li, Kim A Munro, Mina Narouz, Bin Hao, Cathleen M Crudden, J Hugh Horton, Hongxia Hao
Surface chemistry is a key enabler for various biosensing applications. Surface plasmon resonance (SPR)-based biosensors routinely employ thiol-based chemistry for the linker layer between gold-coated support surfaces and functional biosensor surfaces. However, there is a growing awareness that such sensor surfaces are prone to oxidation/degradation problems in the presence of oxygen, and previous efforts to improve the stability have shown limited advancements. As an alternative, recent studies employing N-heterocyclic carbene (NHC) self assembled monolayers (SAMs) deposited on gold have shown significant promise in this area...
October 19, 2017: ACS Applied Materials & Interfaces
Guowen An, Xiaopeng Hao, Shuguang Li, Xin Yan, Xuenan Zhang
A type of D-shaped photonic crystal fiber sensor based on surface plasmon resonance (SPR) is proposed for refractive index sensing and analyzed by the finite element method. The SPR effect between surface plasmon polariton modes and fiber core modes of the designed D-shaped photonic crystal fiber is used to measure the refractive index of the analyte. Numerical results show that the sensor can detect a range of refractive index ranging from 1.33 to 1.38. When the thickness of metal film is t=20  nm, the maximum sensitivity of 10,493  nm/RIU is obtained with a very high resolution of 9...
August 20, 2017: Applied Optics
Xianchao Yang, Ying Lu, Baolin Liu, Jianquan Yao
A surface plasmon resonance (SPR) sensor based on D-shaped microstructured optical fiber (MOF) is proposed to realize the simultaneous measurement of refractive index (RI) and temperature. The D-shaped flat surface coated with a gold layer is in direct contact with analyte as a sensing channel of RI, and one of the air holes near the fiber core is filled with chloroform to detect temperature. Two separate channels and birefringence caused by the asymmetric structure can distinguish the variations of RI and temperature independently, thus completely solving the cross-sensitivity problem...
May 20, 2017: Applied Optics
Yao Shan, Guohang Hu, Liyuan Gu, Hongbo He, Aijun Zeng, Yuanan Zhao, Anna Sytchkova
A setup for surface-plasmon-resonance- (SPR) based imaging ellipsometry was developed, which gains from the sensitivities of both SPR and ellipsometry to ultrathin film parameters. It is based on Otto's configuration for prism-sample coupling and a wide-beam imaging ellipsometry. A set of ultrathin gold and silver films was measured to determine their optical constants and thicknesses. Coupling the sample using a prism with a convex surface enables us to capture images of generated SPR elliptical fringes, which correspond to different SPR amplitude values at different air gap thicknesses...
October 1, 2017: Applied Optics
Ibrahim Watad, Ibrahim Abdulhalim
There is a debate on whether phase measurement in surface plasmon resonance (SPR) sensors give better resolution than intensity measurement. In this work, we show that each one of the modes can give better resolution depending on the metal layer thickness chosen, as well as the available noise levels in the system. We propose a three point polarimetric approach to extract the ellipsometric parameters and phase information in the spectral mode. It is shown that the polarimetric measurement at its optimal thickness range gives up to seven-fold higher resolution than the intensity, especially at noise levels of off the shelf spectrometers...
September 20, 2017: Applied Optics
Yuan Ni, Caixia Kan, Juan Xu, Yang Liu, Haiying Xu, Changshun Wang
The optical properties of coupled plasmon systems can be tuned by individual material and geometry, gap distance, and surrounding dielectric. This paper reports a dramatic effect of a curved interface in the nanoparticles dimer on the optical responses. Compared with gold nanorod (AuNR) monomer, AuNR dimers with different assembly types (such as end-to-end and side-by-side) can manipulate the longitudinal surface plasmon resonance (SPRL) to red/blueshift. The electromagnetic field of the dimer is further enhanced in the interactive region...
October 10, 2017: Applied Optics
Tiesheng Wu, Yu Shao, Ying Wang, Shaoqing Cao, Weiping Cao, Feng Zhang, Changrui Liao, Jun He, Yijian Huang, Maoxiang Hou, Yiping Wang
The refractive index sensing characteristics of the side-polished photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor are detailed investigated in this paper. We used the finite element method (FEM) to study the influences of the side-polished depth, air hole size, lattice constant, and the refractive index (RI) of the PCF material on sensing performance. The simulation results show that the side-polished depth, air hole size, lattice pitch have significant influence on the coupling strength between core mode and surface plasmon polaritons (SPPs), but have little influence on sensitivity; the coupling strength and sensitivity will significant increase with the decrease of RI of the PCF material...
August 21, 2017: Optics Express
Changjian Guo, Yicheng Zheng, Han Zhang
A new inter-block precoding-based channel estimation (CE) scheme is proposed and experimentally demonstrated in an optical OFDM system with a superimposed pilot (SP). The proposed inter-block precoding scheme targets on eliminating the statistical mean of the unknown data symbols, and thereby improves the performance of SP-aided CE. We investigate the impact that both the precoding matrix and SP have on the system performance, from which we obtain the optimum value of signal-to-pilot power ratio (SPR) as well as the block length...
September 18, 2017: Optics Express
Lan Luo, Xiaodong Qiu, Linguo Xie, Xiong Liu, Zhaoxue Li, Zhiyou Zhang, Jinglei Du
In this paper, a method to improve the precision of prism-coupler-based surface plasmon resonance (SPR) sensors using weak-value amplification (WVA) is presented. A general theory model to describe the post-selected SPR sensing system is established and the polarization-dependent amplitude and phase evolutions induced by the SPR are regarded as the weak interactions in the WVA formalism. As a consequence of WVA, the detected signal can be enhanced with respect to the technical noise which is dependent on the post-selected light intensity...
September 4, 2017: Optics Express
Yong Wei, Yudong Su, Chunlan Liu, Yonghui Zhang, Xiangfei Nie, Zhihai Liu, Yu Zhang, Feng Peng
By using a seven-core fiber (SCF), we propose and demonstrate a novel segmented detection SPR sensor, which solves two bottlenecks about the fiber SPR sensor of low sensitivity and the difficulty in the multichannel detection. The proposed sensor has ultra high sensitivity and wide detection range because of employing the segmented detection technology. Besides that, the proposed sensor employs reflection-type time division multiplexing (TDM) technology in fiber multichannel detection for the first time. We couple light into and out of the six circularly symmetric distributed cores of the seven-core fiber to realize the three channel SPR sensing and testing...
September 4, 2017: Optics Express
Gitanjali Kolhatkar, Julien Plathier, Alain Pignolet, Andreas Ruediger
The effect of gold tip crystallinity on their spectral amplification characteristics, monitored through the luminescence enhanced by surface plasmon resonance (SPR), is investigated experimentally. As the tip radius increases, the grains composing polycrystalline tips become larger, resulting in a blueshift of the emission while a redshift of the SPR was predicted for monocrystalline gold. This reveals that the effect of the grain size, a parameter that has not been considered so far, is dominant over that of the tip radius...
October 16, 2017: Optics Express
Masashi Taniguchi, Hiroshige Tateuchi, Satoko Ibuki, Noriaki Ichihashi
BACKGROUND: Trunk axial rotation is a risk factor for chronic low back pain (CLBP). The characteristics of rotational mobility in the pelvis and spine among CLBP patients are not fully understood. PURPOSE: The purpose of this study was to examine three-dimensional kinematic changes, and to compare the differences of rotational mobility and coupled motion, in patients with and without CLBP. METHODS: Fifteen patients with CLBP and 15 age and sex matched healthy subjects participated in this study...
2017: PloS One
Weishan Zhuge, Ruijie Chen, Katanaev Vladimir, Xidan Dong, Khan Zia, Xiangwei Sun, Xuanxuan Dai, Miao Bao, Xian Shen, Guang Liang
Colon cancer is one of the leading causes of cancer-related deaths. A natural sesquiterpene lactone, costunolide (CTD), showed inhibition of cancer development. However, the underlying mechanisms are not known. Here, we have examined the therapeutic activity and novel mechanisms of the anti-cancer activities of CTD in colon cancer cells. Using SPR analysis and enzyme activity assay on recombinant TrxR1 protein, our results show that CTD directly binds and inhibits the activity of TrxR1, which caused enhanced generation of ROS and led to ROS-dependent endoplasmic reticulum stress and cell apoptosis in colon cancer cells...
October 13, 2017: Cancer Letters
Caroline R Basso, Claudia C Tozato, Bruno P Crulhas, Gustavo R Castro, João Pessoa A Junior, Valber A Pedrosa
The aim of the present research is to propose a new method based on localized surface plasmon resonance (LSPR) for fast dengue virus detection. A pool with four dengue serotypes (DENV-1, -2, -3, -4) was detected through antigen-antibody binding using gold nanoparticles (AuNPs) as signaling antibody carriers. Such result was confirmed through surface plasmon resonance (SPR), transmission electron microcopy (TEM), and dynamic light scattering (DLS) techniques. The limit of detection was calculated for TCID50 10(7) demonstrating a linear correlation between viral concentration and number of cells with an r(2) value of > 0...
October 13, 2017: Virology
Alessandro Bellino, Giusy Lofrano, Maurizio Carotenuto, Giovanni Libralato, Daniela Baldantoni
Antibiotics are emerging pollutants released into the environment through wastewater and manure or effluents from livestock plants. Compared to the wide literature on the effects of antibiotics on the development of drug-resistant bacteria and on the adverse effects on animals and human beings, the effects on plants are less investigated. Here we evaluated the effects of four antibiotics (cloramphenicol: CAP, spiramycin: SPR, spectinomycin: SPT, vancomycin: VAN) belonging to different chemical groups, on seed germination and root development of tomato (Solanum lycopersicum L...
October 13, 2017: Ecotoxicology and Environmental Safety
Javier Yanci, Daniel Castillo, Aitor Iturricastillo, Tomás Urbán, Raúl Reina
PURPOSE: The aim of this study was to determine and to compare the external match load (ML), according to sport class (FT) of footballers with cerebral palsy (CP) during the International Federation of CP Football (IFCPF) World Championships Qualification Tournament. METHODS: Forty-two international male footballers with CP participated in the data collection. The footballers with CP were classified according to their FT in three groups (i.e. FT5/6, FT7, and FT8)...
October 16, 2017: International Journal of Sports Physiology and Performance
Chi Lok Wong, Marissa Chua, Heather Mittman, Li Xian Choo, Hann Qian Lim, Malini Olivo
In this paper, we present a phase-intensity surface plasmon resonance (SPR) biosensor and demonstrate its use for avian influenza A (H5N1) antibody biomarker detection. The sensor probes the intensity variation produced by the steep phase response at surface plasmon excitation. The prism sensor head is fixed between a pair of polarizers with a perpendicular orientation angle and a forbidden transmission path. At SPR, a steep phase change is introduced between the p- and s-polarized light, and this rotates the polarization ellipse of the transmission beam...
October 16, 2017: Sensors
Jan Chochol, Kamil Postava, Michael Čada, Jaromír Pištora
We experimentally demonstrate surface plasmon resonance (SPR) in the terahertz range in InSb and InAs. The surface plasmon is excited on the interface between a thin polymer film and the semiconductor using a silicon prism in Otto configuration. The low effective mass of InSb and InAs permits tuning of the SPR by an external magnetic field in the transversal configuration. The data show a good agreement with a model. Strong excitation of the surface plasmon is present in both materials, with a shifting of resonance position by more than 100 GHz for the field of 0...
October 13, 2017: Scientific Reports
Shinji Fukushima, Tomoko Kiyohara, Koji Ishii, Takashi Nakano, Atsuo Hamada
BACKGROUND: Hepatitis A vaccination is recommended for travelers to endemic countries. Several inactivated aluminum-adsorbed hepatitis A vaccines are available worldwide, but only one licensed hepatitis A vaccine is available in Japan. This vaccine is a lyophilized inactivated aluminum-free hepatitis A vaccine (Aimmugen®). The standard schedule of Aimmugen® is three doses (at 0, 2-4 weeks, and 6 months). Japanese people will go abroad after receiving 2 doses of Aimmugen®. Some long-term travelers will receive the third dose of hepatitis A vaccine at their destination, at 6-24 months after 2 doses of Aimmugen®...
October 10, 2017: Vaccine
Suresh K Verma, Ealisha Jha, Pritam Kumar Panda, Anurag Mishra, Arun Thirumurugan, Biswadeep Das, S K S Parashar, Mrutyunjay Suar
In this study, rapid one step facile synthesis of silver nanoparticles (AgNP) was done using culture supernatant of two Gram positive (B.thuringiensis, S.aureus) and Gram negative (E.coli, S.typhimurium) bacterial strains and were termed as "BTAgNP", "SAAgNP", "ECAgNP" and "STAgNP" respectively. Synthesized AgNPs were well characterized with the help of different standard techniques like FESEM, DLS, UV-Vis spectroscopy and FTIR. Mechanism of AgNPs synthesis was elucidated using in silico approach. In vivo cytotoxicity of synthesized AgNPs was assessed in embryonic Zebrafish model with the help of uptake, oxidative stress and apoptosis induction experimental assays and the mechanism was investigated through in silico approach at the molecular level...
September 28, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
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