In this paper, the performances of a wavelength interrogation-based optical fiber surface plasmon resonance sensor for hemoglobin (Hb) concentration is investigated by theoretical simulation. The proposed configuration incorporates optical fiber, 70 nm silver, 18 nm barium titanate (BaTiO3), and 2 nm zinc oxide. Simulation results show the sensor exhibits refractive index sensitivity of 4023 nm/RIU and concentration sensitivity of 10.0873 nm/(g∙dL), along with Hb concentration varying from 0 to 14 g/dL. This paper especially focuses on the influence of BaTiO3 on the performances of the proposed sensor with light wavelength ranging from 350 to 1000 nm. Comparison analysis indicates sandwiching 18 nm BaTiO3 between sensing layers not only enhances the concentration sensitivity by 30.14% but also decreases the nonlinear error of the sensor from 0.68% to 0.63%. For a wavelength accuracy of 0.1 nm, the proposed sensor can provide a resolution of 0.0099 g/dL for Hb concentration detection.
Kretschmann-based surface plasmon resonance (K-SPR) is suitable for biomolecular sensing which provides label-free and quick detection results with real-time analysis. In this work, we have investigated the effect of graphene oxide (GO) with titanium dioxide (TiO2) thin films that are placed in hybrid above metal layers such as gold (Au), silver (Ag) and copper (Cu) with the presence of chromium (Cr) as an adhesive layer. The thickness of the Au, Ag and Cu metal thin films were optimized to 40, 30 and 30 nm, respectively, with a fixed thickness of GO of 2 nm and TiO2 of 1.9 nm. The sensing was evaluated for SPR excitation at three different visible wavelengths of 633, 670 and 785 nm. The performance of sensing was analyzed based on the reflectance intensity and full-width at half-maximum (FWHM) of the spectrum using the finite-difference time-domain (FDTD) method. The sensitivity was calculated for analyte sensing in dielectric mediums of air versus water. The sensitivity increment percentage (%∆S ) was determined when comparing analyte detection using Cr/metal and Cr/metal/GO/TiO2 sensor structures. The highest sensitivity of 94.51 deg/RIU was achieved for Cr/Cu/GO/TiO2 K-SPR sensor at 633 nm wavelength.
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The relationship between microscopic parameters of surface nanostructure and output characteristics of the photoacoustic transducer is established in this paper. In this paper, novel results in the area of complex simulation of thermal, acoustic and mechanical characteristics of surface nanostructures are demonstrated. The design of fiber-optic photoacoustic ultrasound transducer providing the most effective optical-to-acoustic conversion (intensity modulated optical signal is converted into pressure waves) is proposed as a result comprehensive theoretical study of absorbed optical power, stationary and non-stationary temperature and pressure distribution in various surroundings for different sets of microscopic parameters of surface nanostructures on the optical fiber edge. Additionally, the photoacoustic response is measured in order to provide the experimental proof of main results. Obtained dependencies can be used in the design of modern and perspective systems of ultrasound technical diagnostics, high-resolution ultrasound imaging of industrial densely-packed objects.
PL
W pracy przedstawiono zależność między parametrami mikroskopowymi nanostruktury powierzchniowej a wyjściowymi właściwościami akustycznymi przetwornika fotoakustycznego. W tym artykule przedstawiono nowatorskie wyniki w dziedzinie złożonej symulacji termicznych, akustycznych i mechanicznych właściwości nanostruktur powierzchniowych. Proponuje się zaprojektowanie światłowodowego fotoakustycznego przetwornika ultradźwiękowego zapewniającego najskuteczniejszą konwersję optyczno-akustyczną (sygnał optyczny o modulowanym natężeniu zamienia się w fale ciśnieniowe) w wyniku kompleksowych badań teoretycznych pochłoniętej mocy optycznej, stacjonarnej i niestacjonarnej temperatury oraz rozkład ciśnienia w różnych środowiskach dla różnych zestawów parametrów mikroskopowych powierzchniowych nanostruktur na krawędzi światłowodu. Dodatkowo mierzona jest odpowiedź fotoakustyczna w celu dostarczenia eksperymentalnego dowodu głównych wyników. Uzyskane zależności można wykorzystać przy projektowaniu nowoczesnych i perspektywicznych systemów ultradźwiękowej diagnostyki technicznej, obrazowania ultradźwiękowego wysokiej rozdzielczości gęsto upakowanych obiektów przemysłowych.
In this paper, sensitivity enhancement of a nanocomposite-based optical fiber sensor with platinum nanoparticles is investigated. This optical fiber sensor is based on the surface plasmon resonance in the nanocomposite layer coating the core of optical fiber. A comparison is carried out for sensitivity between an optical fiber sensor based surface plasmon resonance with platinum layer and the one with nanocomposite layer. The nanocomposite layer consists of platinum nanoparticles with varying volume fraction which is arrayed in a host dielectric material of InN or TiO2. We show that the sensitivity of the sensor with a nanocomposite layer containing platinum nanoparticles is bigger than the sensitivity of the sensor with a platinum layer for all the values of refractive index of sample media. Also, the effect of the thickness of the nanocomposite layer and the volume fraction of platinum nanoparticles on the spectrum of the transmitted power has been investigated.
A polarization photonic crystal fiber based on surface plasmon resonance is proposed in this paper. The photonic crystal fiber with gold coated holes is studied through using the finite element method. The impacts of structural parameters on the resonance characteristics are discussed. Numerical simulations show that the resonance wavelength can be modulated by changing the parameters of the air holes and thickness of gold layer. At the resonance wavelength 1550 nm, the loss is 3.8045 dB/m in x-polarization and the loss is 28464 dB/m in y-polarization by adjusting the size of the gold-coated holes and the place of air holes. Results show that the loss of y-polarized mode is much larger than the loss of x-polarized mode. The y-polarized mode is suppressed, and only x-polarized mode can be guided at the resonance wavelength of y-polarized mode. The results indicate that the mode polarized in one direction can be filtered out selectively by adjusting the diameter of air holes, and the filtering effect in a communication band is achieved.
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A surface-plasmon-resonance (SPR) sensor based on photonic-crystal-fiber (PCF) with large size microfluidic channels is proposed. The size of the microfluidic channels with gold coating can be enlarged by reducing the number of the holes in the second layer, so the structure of the PCF is simple and easy to manufacture. It is propitious for metal coating and infiltration of microfluidic. The contact area of sample and metal film is increased, and the interface is closer to the core, so the energy coupling between the plasmon mode and the core-guided mode is easier. Numerical results indicate that the excitation of the plasmon mode is sensitive to the change of the refractive index of adjacent analyte. Sensitivity of the sensor is comparable to the ones of the best existing waveguide sensors. The amplitude resolution is demonstrated to be as low as 3.3×10-5 RIU, and the spectral resolution is 5×10-6 RIU (where RIU means the refractive index unit). The refractive index of microfluidic can be measured effectively.
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Silver nanowire filled photonic crystal fibers are proposed in this paper to achieve surface plasmon resonance sensors and overcome the complicacy and difficulty of coating the holes in the photonic crystal fiber. Optical field distributions of these fibers at different wavelengths are calculated and simulated using the finite element method (FEM), and the sensing properties are discussed in both areas of resonant wavelength and intensity detection. Numerical simulation results show that carefully designed structure of the sensor brings about an excellent effect, with both spectral and intensity sensitivity in the range of 4×10-5-5×10-5 RIU, better than in the case of similar structures coated with metal film, and the fabrication is expected to be simplified.
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The cross-linked chitosan is synthesized by homogeneous reaction of medium molecular weight chitosan in aqueous acetic acid solution with glutaraldehyde as cross-linking agent. Using surface plasmon resonance technique, the optical properties of cross-linked chitosan thin film before and after contacting with different concentrations of copper ion in a range of 0 to 100 ppm had been obtained by fitting. The imaginary part of refractive index increased while the thickness of the film decreased as copper ion concentration increased from 0 (deionised water) to 100 ppm. The resonance angle shifted to lower value as the copper ion concentration increased. By introducing the cross-linked chitosan film, copper ion detection can be obtained for concentration as low as 0.5 ppm using surface plasmon resonance technique.
The smart portable devices for express-diagnostics of photosynthesis and acute viral infections are designed in the V.M. Glushov Institute of Cybernetics of National Academy of Sciences of Ukraine in collaboration with National University of Life and Environmental Sciences of Ukraine. The first device is based on the measurements of chlorophyll fluorescence induction without plant destruction and the second one - on the effect of surface plasmon resonance. The features of devices are considered in the article.
PL
Instytut Cybernetyki Narodowej Akademii Nauk im. V.M. Glushov na Ukrainie we współpracy z Narodowym Uniwersytetem Życia i Nauk Środowiska na Ukrainie zaprojektował inteligentne przenośne urządzenia do szybkiej diagnostyki fotosyntezy oraz ostrych infekcji wirusowych. Pierwsze urządzenie jest oparte na pomiarach indukcji fluorescencji chlorofilu bez zniszczenia rośliny. Druga natomiast na zjawisku powierzchniowego rezonansu plazmonowego. Właściwości urządzeń opisane są w artykule.
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Absorbing and emitting optical properties of a spherical plasmonic nanoantenna are described in terms of the size dependent resonance frequencies and damping rates of the multipolar surface plasmons (SP). We provide the plasmon size characteristics for gold and silver spherical particles up to the large size retardation regime where the plasmon radiative damping is significant. We underline the role of the radiation damping in comparison with the energy dissipation damping in formation of receiving and transmitting properties of a plasmonic particle. The size dependence of both: the multipolar SP resonance frequencies and corresponding damping rates can be a convenient tool in tailoring the characteristics of plasmonic nanoantennas for given application. Such characteristics enable to control an operation frequency of a plasmonic nanoantenna and to change the operation range from the spectrally broad to spectrally narrow and vice versa. It is also possible to switch between particle receiving (enhanced absorption) and emitting (enhanced scattering) abilities. Changing the polarization geometry of observation it is possible to effectively separate the dipole and the quadrupole plasmon radiation from all the non-plasmonic contributions to the scattered light.
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Due to resonant excitation of surface plasmons, surface plasmon resonance (SPR) sensors combined with ferromagnetic thin films allow an enhancement of the magneto-optical (MO) response. MO-SPR structures with Au/Co/Au sandwiches are theoretically analyzed in transverse configuration by 4×4 matrix algebra. The influence of sandwich film thickness, layer order and Co-Au multilayers on the relative change of the reflectance for p-polarized waves is analyzed. The results show the important role of the incidence angle distribution of the reflectance without magnetic ordering on the MO-SPR response. An optimized geometry and a corresponding feedback are discussed.
Sensors based on surface plasmon resonance (SPR) are widespread in modern devices of biochemical application. As a rule, a technique of diagnostic is a measurement of angle dependence of the refraction index from incident angle of p-polarised monochromic light R( ) from the substrate at plasmon excitation supporting metal film contacted by enviro nment or layer under investigation. Potentialities of SPR sensors may be extended with the inclusion of additional dielectric films into the structure of SPR substrates.
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The use ofthe Surface Plasmon Resonance phenomenon to create a two-dimensional image of a surface has become of importance in the field of proteornics and in the study ofthe interactions between biomolecules. One ofthe most critical steps in the preparation of a sample for Surface Plasmon Resonance measurements is the immobilization ofthe molecules on the metallic surface (usually gold). The most common procedure, implies the creation of a Self Assembled Monolayer of a thiol on the surface ofthe chip and the subsequent immobilization of biomolecules on it. In this paper, we describe a procedure of gold modification to bind proteins, and its application to study protein-protein interactions.
PL
Użycie zjawiska powierzchniowego rezonansu plazmonów do tworzenia przestrzennych obrazów powierzchni odgrywa ważna rolę wproleomice i badaniach oddziaływań biomo-lekuł. Jednym z najważniejszych kroków w przygotowaniu próbki do pomiarów metodą powierzchniowego rezonansu plazmonówjest proces immobilizacji biomolckul na metalicznej powierzchni (zazwyczaj złota). Najczęściej proces ten przebiega przez utworzenie mono warstwy tiolu na powierzchni złota, na której są immobilizowane biomolekuły. W pracy opisano procedurę modyfikacji powierzchni złota do immobilizacji biomolekuł i jej zastosowanie do badań interakcji białek.
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Surface Plasmon Resonance (SPR) has been successfully used in accessing information on a variety of molecular interactions and has achieved a wider popularity with the commercial availability of the BiaCoreŽ system. A new variation of this technique, SPR Imaging, allows the visualisation of 2D areas and provides an alternative method to the existing detection schemes of biochips. Here we report on methods to optimise the surface chemistry of the gold layer and to properly immobilise probe molecules. The parameters studied include gold thickness, adhesive metal iayer, cleaning procedures, different immobilization methods
PL
Metoda rezonansu plazmonów powierzchni (SPR) została z powodzeniem zastosowana do poznania różnorodnych oddziaływań uzyskując szerszą popularność w związku z dostępnością systemu BiaCoreŽ. Nowa technika obrazowania SPR pozwala na dwuwymiarową (2D) wizualizację powierzchni i jest alternatywna metodą w stosunku do istniejących sposobów detekcji dla bioczipów. W pracy podano metody optymalizacji chemizmu powierzchni warstw złota i prawidłowego unieruchomiania cząsteczek próbnikowych. Wśród badanych parametrów jest grubość warstwy złota, adhezyjnej warstwy, procedur czyszczenia i różnych sposobów immobilizacji.
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The paper deals with investigations concerning the optical parametersof the layers of selected phthalocyanines by means of the surface plasmon resonance method. the values of the refracting index and the coefficient of extinction for copper and lead phthalocyanines have been determined. the presented results concern the layers occurring in the surrounding atmospheric air before and after exposure to 100 ppm nitrogen dioxide. The obtained dispersive characteristics were determined ellipsometrically and using the surface plasmon resonance method, by adapting theoretical relations to the experimental dependenceof the surface plasmon resonance. The resulting values of the complex refracting index for the tested phthalocyanines were comparedwith the values obtained by ellipsometric measurements.
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The surface plasmon resonance spectroscopy is an optical technique that is capable of monitoring chemical and physical processes. It is sensitive to detect small changes of dielectric properties in a metal-phthalocyanine boundary. For this reason plasmon resonance phenomena have been used to characterize a number of different types of films. This work analyses the possibility of using the surface plasmon resonance phenomena in the detection of gas. Thin films of copper, lead and nickel phthalocyanines have been examined in the plasmon system from the point of view of their application to NO2 sensors
The paper deals with investigations concerning the optical parameters of the layers of selected phthalocyanines by means of the surface plasmon resonance method. The values of the refracting index and the coefficient of extinction for copper and lead phthalocyanines have been determined. The presented results concern the layers occurring in the surrounding atmospheric air before and after exposure to 100ppm nitrogen dioxide. The obtained dispersive characteristics were determined ellipsometrically and using the surface plasmon resonance method, by adapting theoretical relations to the experimental dependence of the surface plasmon resonance. The resulting values of the complex refracting index for the tested phthalocyanines were compared with the values obtained by ellipsometric measurements.
The surface plasmon resonance spectroscopy is a technique that is capable of monitoring chemical and physical processes. It is sensitive to detect small changes of dielectric properties in a metal-phthalocyanine boundary. For this reason plasmon resonance phenomena have been used to characterize a number of different types of films. This work analyses the possibility of using the surface plasmon resonance phenomena in the detection of gas. Thin films of copper and lead phthalocyanines have been examined in the plasmon system from the point of view of their application in NO2 sensors.
Surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) studies are described for tetrakis-tert-butylphthalocyanatoCu(II) and two new tetrakis-5,10,15,20- (substituted phenyl)-21H,23H-porphines. The Langmuir isotherms of the porphines, coupled with the layer thickness and contact area of the LB monolayers, show that these two compounds are not forming regular monolayer LB films, but are exhibiting extensive clumping on the subphase and on the substrates. The optical spectra and SPR of the porphine films did not exhibit noteworthy sensitivity to chlorine. In contrast the phthalocyanine gave good quality monolayers, which showed promise for sensing chlorine in the 1-10 ppm range.
In the group of new sensory meterials, phthalocyanineas posses very attractive physical and chemical properties. For some years, phtalocyanineas are investigated for applying in acoustic as well as in optic gas sensors. This work analyzes the possibility of using the surface plasmon resonance system for lead phthalocyjanineas investigations for NO2 sensor applications.
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