scholarly journals Optimization Based on the Surface Plasmon Optical Properties of Adjustable Metal Nano-Microcavity System for Biosensing

2021 ◽  
Vol 9 ◽  
Author(s):  
Jin Zhu ◽  
Yiye Yang ◽  
Yanping Yin ◽  
Huining Yuan
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
Gold Film ◽  
Incident Light ◽  
Extinction Spectrum ◽  
High Sensitivity ◽  
Element Analysis ◽  
Environmental Media ◽  
Resonance Modes ◽  
High Concentrations

This paper mainly studies the plasma optical properties of the silver nanorod and gold film system with gap structure. During the experiment, the finite element analysis method and COMSOL Multiphysics are used for modeling and simulation. The study changes the thickness of the PE spacer layer between the silver nanorod and the gold film, the conditions of the incident light and the surrounding environment medium. Due to the anisotropic characteristics of silver nanorod, the microcavity system is extremely sensitive to the changes of internal and external conditions, and the system exhibits strong performance along the long axis of the nanorod. By analyzing the extinction spectrum of the nanoparticle and the electric field section diagrams at resonance peak, it is found that the plasma optical properties of the system greatly depend on the gap distance, and the surrounding electric field of the silver nanorod is confined in the gap. Both ends of the nanorod and the gap are distributed with high concentrations of hot spots, which reflects the strong hybridization of multiple resonance modes. Under certain excitation conditions, the plasma hybridization behavior will produce a multi-pole mode, and the surface electric field distribution of the nanorod reflects the spatial directionality. In addition, the system is also highly sensitive to the environmental media, which will cause significant changes in its optical properties. The plasma microcavity system with silver nanorod and gold film studied in this paper can be used to develop high-sensitivity biosensors, which has great value in the field of biomedical detection.

scholarly journals Novel nano-plasmonic sensing platform based on vertical conductive bridge

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hyo-Seung Park ◽  
Jongkil Park ◽  
Joon Young Kwak ◽  
Gyu-Weon Hwang ◽  
Doo-Seok Jeong ◽  
...  
Keyword(s):  
Electric Field ◽  
Incident Light ◽  
Geometrical Parameters ◽  
Theoretical Simulation ◽  
Resonance Modes ◽  
High Tunability ◽  
Fluid Analysis ◽  
Plasmonic Sensing ◽  
Sensing Platform ◽  
Conductive Bridge

AbstractA novel nano-plasmonic sensing platform based on vertical conductive bridge was suggested as an alternative geometry for taking full advantages of unique properties of conductive junction while substantially alleviating burdens in lithographic process. The effects of various geometrical parameters on the plasmonic properties were systematically investigated. Theoretical simulation on this structure demonstrates that the presence of vertical conductive bridge with smaller diameter sandwiched between two adjacent thin nanodiscs excites a bridged mode very similar to the charge transfer plasmon and exhibits a remarkable enhancement in the extinction efficiency and the sensitivity when the electric field of incident light is parallel to the conductive bridge. Furthermore, for the electric field perpendicular to the bridge, another interesting feature is observed that two magnetic resonance modes are excited symmetrically through open-gaps on both sides of the bridge together with strongly enhanced electric field intensity, which provides a very favorable environment as a surface enhanced Raman scattering substrate for fluid analysis. These results verify a great potential and versatility of our approach for use as a nanoplasmonic sensing platform. In addition, we demonstrated the feasibility of fabrication process of vertical conductive bridge and high tunability in controlling the bridge width.

Dependence of optical properties of monoclinic MnWO4 on the electric field of incident light

2012 ◽  
Vol 407 (17) ◽  
pp. 3654-3659 ◽  
Author(s):  
Lu-Gang Cai ◽  
Fa-Min Liu ◽  
Dian Zhang ◽  
Wen-Wu Zhong
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
Incident Light

scholarly journals Magnetoelastic Coupling and Delta-E Effect in Magnetoelectric Torsion Mode Resonators

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2022
Author(s):  
Benjamin Spetzler ◽  
Elizaveta V. Golubeva ◽  
Ron-Marco Friedrich ◽  
Sebastian Zabel ◽  
Christine Kirchhof ◽  
...  
Keyword(s):  
Low Frequency ◽  
High Sensitivity ◽  
Element Model ◽  
Mode Number ◽  
Frequency Change ◽  
General Description ◽  
Resonance Modes ◽  
Field Sensor ◽  
Magnetic Sensitivity ◽  
Bending Modes

Magnetoelectric resonators have been studied for the detection of small amplitude and low frequency magnetic fields via the delta-E effect, mainly in fundamental bending or bulk resonance modes. Here, we present an experimental and theoretical investigation of magnetoelectric thin-film cantilevers that can be operated in bending modes (BMs) and torsion modes (TMs) as a magnetic field sensor. A magnetoelastic macrospin model is combined with an electromechanical finite element model and a general description of the delta-E effect of all stiffness tensor components Cij is derived. Simulations confirm quantitatively that the delta-E effect of the C66 component has the promising potential of significantly increasing the magnetic sensitivity and the maximum normalized frequency change ∆fr. However, the electrical excitation of TMs remains challenging and is found to significantly diminish the gain in sensitivity. Experiments reveal the dependency of the sensitivity and ∆fr of TMs on the mode number, which differs fundamentally from BMs and is well explained by our model. Because the contribution of C11 to the TMs increases with the mode number, the first-order TM yields the highest magnetic sensitivity. Overall, general insights are gained for the design of high-sensitivity delta-E effect sensors, as well as for frequency tunable devices based on the delta-E effect.

scholarly journals Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1768
Author(s):  
Miroslav Rievaj ◽  
Eva Culková ◽  
Damiána Šandorová ◽  
Zuzana Lukáčová-Chomisteková ◽  
Renata Bellová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Element ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Short Review ◽  
Electroanalytical Methods ◽  
High Concentrations ◽  
Speed Of Analysis

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.

Computational study on strain and electric field tunable electronic and optical properties of InTe monolayer

2021 ◽  
Vol 151 ◽  
pp. 106816
Author(s):  
Thi-Nga Do ◽  
Vo T.T. Vi ◽  
Nguyen T.T. Binh ◽  
Nguyen N. Hieu ◽  
Nguyen V. Hieu
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
Computational Study ◽  
Electronic And Optical Properties

scholarly journals Polymer Dispersed Cholesteric Liquid Crystals With a Toroidal Director Configuration under an Electric Field

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 732
Author(s):  
Anna P. Gardymova ◽  
Mikhail N. Krakhalev ◽  
Victor Ya. Zyryanov ◽  
Alexandra A. Gruzdenko ◽  
Andrey A. Alekseev ◽  
...  
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Electric Field ◽  
Point Defects ◽  
Structural Response ◽  
Optical Filters ◽  
Response Curves ◽  
Polymer Dispersed Liquid Crystal ◽  
Dichroic Dye ◽  
Polymer Dispersed

The electro-optical properties of polymer dispersed liquid crystal (PDLC) films are highly dependent on the features of the contained liquid crystal (LC) droplets. Cholesteric LC droplets with homeotropic boundaries can form several topologically different orientational structures, including ones with single and more point defects, layer-like, and axisymmetric twisted toroidal structures. These structures are very sensitive to an applied electric field. In this work, we have demonstrated experimentally and by computer simulations that twisted toroidal droplets reveal strong structural response to the electric field. In turn, this leads to vivid changes in the optical texture in crossed polarizers. The response of droplets of different sizes were found to be equivalent in terms of dimensionless parameters. In addition, the explanation of this phenomenon showed a comparison of theoretical and experimental structural response curves aids to determine the shape of the droplet. Finally, we demonstrated that the addition of a dichroic dye allows such films to be used as optical filters with adjustable color even without polarizers.

scholarly journals Sensing Electrochemical Signals Using a Nitrogen-Vacancy Center in Diamond

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 358
Author(s):  
Hossein T. Dinani ◽  
Enrique Muñoz ◽  
Jeronimo R. Maze
Keyword(s):  
Electric Field ◽  
Electron Spin ◽  
Electrolyte Solution ◽  
High Sensitivity ◽  
Theoretical Work ◽  
Coherence Time ◽  
Nitrogen Vacancy ◽  
Local Concentration ◽  
Concentration Of Ions ◽  
Nv Center

Chemical sensors with high sensitivity that can be used under extreme conditions and can be miniaturized are of high interest in science and industry. The nitrogen-vacancy (NV) center in diamond is an ideal candidate as a nanosensor due to the long coherence time of its electron spin and its optical accessibility. In this theoretical work, we propose the use of an NV center to detect electrochemical signals emerging from an electrolyte solution, thus obtaining a concentration sensor. For this purpose, we propose the use of the inhomogeneous dephasing rate of the electron spin of the NV center (1/T2★) as a signal. We show that for a range of mean ionic concentrations in the bulk of the electrolyte solution, the electric field fluctuations produced by the diffusional fluctuations in the local concentration of ions result in dephasing rates that can be inferred from free induction decay measurements. Moreover, we show that for a range of concentrations, the electric field generated at the position of the NV center can be used to estimate the concentration of ions.

scholarly journals Design of a Liquid-Crystal-Tunable Terahertz Demultiplexer Based on a Metal-Insulator-Metal Waveguide

2019 ◽  
Vol 9 (4) ◽  
pp. 644
Author(s):  
Xue-Shi Li ◽  
Naixing Feng ◽  
Yuan-Mei Xu ◽  
Liang-Lun Cheng ◽  
Qing Liu
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Metal Insulator ◽  
Resonance Modes ◽  
External Bias ◽  
Bias Electric Field ◽  
Metal Waveguide ◽  
Metal Insulator Metal ◽  
Fabry Perot ◽  
Mim Waveguide

A tunable demultiplexer with three output channels infiltrated by liquid crystal (LC) is presented, which is based on a metal-insulator-metal (MIM) waveguide. The operating frequencies of the three output channels can be tuned simultaneously at will by changing the external bias electric field applied to the LC. By analyzing the Fabry-Pérot (FP) resonance modes of the finite-length MIM waveguide both theoretically and numerically, the locations of the three channels are delicately determined to achieve the best demultiplexing effects. Terahertz (THz) signals input from the main channel can be demultiplexed by channels 1, 2 and 3 at 0.7135 THz, 1.068 THz and 1.429 THz, respectively. By applying an external electric field to alter the tilt angle of the infiltrating LC material, the operating frequencies of channels 1, 2 and 3 can be relatively shifted up to 12.3%, 9.6% and 9.7%, respectively. The designed demultiplexer can not only provide a flexible means to demultiplex signals but also tune operating bands of output channels at the same time.

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