• Food Science and Biotechnology
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• 제17권3호
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• pp.547-552
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• 2008

The detection of carbamate (carbofuran, carbaryl, benfracarb, thiodicarb, and methomil) and organophosphate (diazinon, cadusafos, ethoprofos, parathion-methyl, and chlorpyrifos) pesticide residues with very low detection limits was carried out using surface plasmon resonance (SPR) based equipment. The capacity to develop a portable SPR biosensor for food safety was also investigated. The applied ligand for the immunoassays was polyclonal goat anti-rabbit immunoglobulin (IgG) peroxidase conjugate. Concentration tests using direct binding assays showed the possibility of quantitative analysis. For ligand fishing to find a proper antibody to respond to each pesticide, acetylcholinesterase (AChE), and glutathione-S-transferase (GST) were tested. The reproducibility and precision of SPR measurements were evaluated. With this approach, the limit of detection for pesticide residues was 1 ng/mL and analysis took less than 11 min. Thus, it was demonstrated that detecting multi-class pesticide residues using SPR and IgG antibodies provides enough sensitivity and speed for use in portable SPR biosensors.

• 센서학회지
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• 제25권4호
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• pp.243-246
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• 2016

The characteristics of a bimetallic surface plasmon resonance (SPR) chip were investigated to detect a tumor biomarker, carcinoembryonic antigen (CEA). The linewidth and the tangential slope of the reflectance curve of the bimetallic SPR chip was compared with those of the reflectance curve of a conventional gold (Au) SPR chip. The changes in reflectance in response to the variation in CEA in the critical concentration range were analyzed at an angle where the tangential slope of the reflectance curve was maximum. From linear regression analysis, the sensitivity of the bimetallic SPR chip with respect to the CEA in critical concentration was obtained.

• 센서학회지
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• 제13권5호
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• pp.342-349
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• 2004

SK (SPR Kinds) index, which can categorize the complicated measurement methods of surface plasmon resonance by simple method, has been proposed and verified. SK index is composed of three digits, where each digit presents the type of immobilized ligand, the type of illumination and the kinds of varying parameter, sequentially. The measurement method of (33#) series among SK indices shows the possibility of the multi-sensing capability, by which the response of 2-dimensional array of immobilized ligands can be detected simultaneously. The proposed possibility of multi-sensing capability has been verified by the modeling that is based on Fresnel reflection model.

• 전기학회논문지
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• 제56권1호
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• pp.156-160
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• 2007

Surface plasmon resonance(SPR) has been widely studied for biological and chemical sensing applications. The present study conducts numerical simulation for the single and bimetallic layer SPR configurations by using the multiple beam interference matrix(MBIM) method to investigate the influence of wave interference and complex refractive indices of materials on optical characteristics such as reflectance and optical phase shift which are used for sensing. First, calculated reflectances are compared with experimental data for validation. In addition, in the single film structures this study finds out the appropriate film thicknesses with minimum reflectance for cases of gold film and silver film. For a bimetallic silver-gold film structure, in particular, the bimetallic film thicknesses that has the minimum reflectance are found 36 nm for silver and 5 nm for gold. From the results, the use of phase shift would be useful compared to reflectance in determining the SPR configuration because the phase shift becomes more sensitive than reflectance.

• ETRI Journal
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• 제29권6호
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• pp.808-810
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• 2007

We demonstrate 10 Gbps optical signal transmission via long-range surface plasmon polaritons (LR-SPPs) in a very thin metal strip-guided geometry. The LR-SPP waveguide was fabricated as a 14 nm thick, 2.5 ${\mu}m$ wide, and 4 cm long gold strip embedded in a polymer and pigtailed with single-mode fibers. The total insertion loss of 16 dB was achieved at a wavelength of 1.55 ${\mu}m$ as a carrier wave. In a 10 Gbps optical signal transmission experiment, the LR-SPP waveguide exhibits an excellent eye opening and a 2.2 dB power penalty at $10^{-12}$ bit error rate. We confirm, for the first time, that LR-SPPs can efficiently transfer data signals as well as the carrier light.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.601-604
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• 2008

We report on the Ag thickness effect on the electrical and optical properties of indium zinc tin oxide (IZTO)-Ag-IZTO multilayer electrode grown on a PET substrate and the surface plasmon effect of Ag layer on the optical properties of IZTO-Ag-IZTO electrode. Using an IZTO-Ag-IZTO multilayer with a total thickness below ~80 nm, we can obtain high-quality flexible electrode with very low sheet resistance, high transmittance, high work function and superior flexibility.

• Current Optics and Photonics
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• 제1권3호
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• pp.239-246
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• 2017

A compact plasmonic switching scheme, based on the phase change of a thin-film chalcogenide material ($Ge_2Sb_2Te_5$), is proposed and numerically investigated at optical-communication wavelengths. Surface plasmon polariton modal analysis is conducted for various thicknesses of dielectric and phase-change material layers, and the optimized condition is induced by finding the region of interest that shows a high extinction ratio of surface plasmon polariton modes before and after the phase transition. Full electromagnetic simulations show that multiple reflections inside the active region may conditionally increase the overall efficiency of the on/off ratio at a specific length of the active region. However, it is shown that the optimized geometrical condition, which shows generally large on/off ratio for any length of active region, can be distinguished by observing the multiple-reflection characteristic inside the active region. The proposed scheme shows an on/off switching ratio greater than 30 dB for a length of a few micrometers, which can be potentially applied to integrated active plasmonic systems.

• 센서학회지
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• 제14권6호
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• pp.402-408
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• 2005

This paper describes the optimal design of a multi-layered surface plasmon resonance sensors to meet various specifications and improve some physical parameters. Dip 3 dB bandwidth and depth were chosen as design parameters and the objective function was the norm of the difference between design parameters and target values. The design variables are thicknesses of each layer and to obtain the design parameters, the optical admittance method was employed. The (1+1) evolution strategy was employed as an optimization tool. By applying the proposed optimization procedure to a 3-layered sensor, the optimized design variables considerably improved the 3 dB bandwidth by 4.8 nm and the dip depth by 1.1 dB.

• 한국동물위생학회지
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• 제30권2호
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• pp.205-209
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• 2007

A protein chip based on surface plasmon resonance (SPR) imaging was developed for measuring classical swine fever virus (CSFV) antibody using a recombinant gp55 protein as an antigen. The diagnostic potential of SPR imaging for detecting antibodies to the CSFV gp55 protein was compared with that of a enzyme -linked immunosorbent assay (ELISA) using 70 pig sera. There was a strong positive correlation between the SPR imaging and ELISA (n=70, r=0.916, p<0.01). Therefore, the SPR imaging, which is a label-free and high-through put method, is expected to be a valuable tool in the serodiagnosis of CSFV.

• Food Science and Biotechnology
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• 제15권3호
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• pp.404-408
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• 2006

Feasibility of surface plasmon resonance (SPR) method to evaluate soybean frying oil quality was evaluated. Free fatty acid value, p-anisidine value, conjugated dienoic acid content, conjugated trienoic acid content, peroxide value, iodine value, total polar compound (TPC), ratio of unsaturated fatty acid to saturated fatty acid, refractive index, dielectric constant, smoking point, and L, a, and b of Hunter color system were selected as parameters related to conventional evaluation of soybean frying oil quality. SPR scale mapped with conventional quality parameters well described free fatty acid value, conjugated dienoic acid content, dielectric constant, TPC, and b of Hunter color system, as shown by correlation and linear regression analyses.