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Journal ArticleDOI

Performance analysis of a plasmonic sensor based on gold nanoparticle film in infrared light using the admittance loci method

27 Feb 2015-Journal of Applied Physics (AIP Publishing)-Vol. 117, Iss: 8, pp 083110

AbstractA theoretical design of surface plasmon resonance (SPR) structure operating in attenuated total reflection (ATR) mode and comprising of silicon or chalcogenide (2S2G) prism material coated with gold film having different nanoparticle sizes has been reported along with some interesting performance related simulation results at the operating wavelength of 1200 nm in infrared The admittance loci based technique has been employed for the appropriate choice of the metal layer thickness The sensitivity and other performance parameters of the structure based on the choice of the high index prism material and correct gold nanoparticle size have also been presented In comparison to other conventional prism based plasmonic structures, the proposed model provides the extra degree of freedom, ie, variations of nanoparticle size in addition to the variation in layer thickness and the use of different high index prism materials like silicon, 2S2G materials, etc Moreover, the width of the SPR curve can be controll more

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Journal ArticleDOI
Abstract: We report on a non-universal behavior of leaky surface plasmon waves on asymmetric (Si/Au/analyte of different height) 1D grating through numerical modelling. The occurrence of the leaky surface wave was maximized (suppressing the Fabry–Perot cavity mode), which can be identified in a reflection spectrum through characteristic minimum. Beyond a specific analyte height (h), new sets of surface waves emerge, each bearing a unique reflection minimum. Furthermore, all of these minima depicted a red-shift before saturating at higher h values. This saturation is found to be non-universal despite the close association with their origin (being leaky surface waves). This behavior is attributed to the fundamental nature and the origin of the each set. Additionally, all of the surface wave modes co-exit at relatively higher h values.

18 citations

Journal ArticleDOI
01 Apr 2016-Optik
Abstract: A plasmonic biosensor comprising of prism as a light coupling material, gold (Au) as a plasmon supporting metal and oxygenated native hemoglobin (Hb) solution as a bio sample operating under attenuated total reflection (ATR) mode has been modelled using the admittance loci method for detecting wavelength and concentration dependent refractive index (RI) variations of oxygenated native Hb solution for 700 nm to 900 nm wavelength in near infrared (NIR). Silicon (Si) and chalcogenide (2S2G) as high refractive index light coupling prism materials have been used in order to investigate their plasmonic biosensing performance in near infrared. The performance issues of the concerned plasmonic biosensor have also been discussed in terms of sensing parameters such as dynamic range, sensitivity, Full Width Half Maximum (FWHM).

2 citations

Proceedings ArticleDOI
15 Jun 2015
Abstract: In this work, admittance loci method is used to model and analyze performance of a chalcogenide prism based plasmonic biosensor comprising of gold metal nanoparticle film for detection of wavelength dependent refractive index change of human blood sample under angular interrogation mode. The wavelength dependent performance of the plasmonic biosensor based on the choice of chalcogenide (2S2G) as a coupling prism material has been discussed with the help of performance parameter plots.

Cites methods from "Performance analysis of a plasmonic..."

  • ...For gold nanoparticle film the modified admittances are given by ( ) i m k m in i p n m k m n s m θ θ η cos 2 / 1 2 2 sin 2 2 2 − − − = (7)...


Journal ArticleDOI
Abstract: Modeling of a fused silica ( SiO 2 ) glass prism-based plasmonic structure comprising of indium oxide ( In 2 O 3 )–zirconium dioxide ( ZrO 2 )–silver (Ag)–zinc oxide (ZnO) intermediate layers showing enhancement in sensitivity and figure-of-merit (FOM) in visible and infrared regime has been reported in this paper. Performance of the proposed plasmonic structure has been demonstrated in terms of sensitivity, half width (HW), detection accuracy (DA), and FOM parameters in visible (632.8 nm) and infrared (1200 nm) wavelength of light. High sensitivity of fused silica glass material, In 2 O 3 , ZnO films along with high DA and high FOM of Ag and inclusion of ZrO 2 as an oxidation protective layer in between In 2 O 3 and Ag have been the most exciting and advantageous features of our proposed structure. Simulated sensitivity values of our proposed structure were found to be 73.8 deg/RIU at 632.8 nm wavelength and it was found enhanced to 109.6 deg/RIU at 1200 nm wavelength and simulated FOM values were also found enhanced from 23.3544 RIU− 1 at 632.8 nm to 62.6285 RIU− 1 at 1200 nm wavelength for change in sensing layer refractive indices from 1.30 RIU to 1.35 RIU.

Additional excerpts

  • ...EQ-TARGET;temp:intralink-;e008;63;448qk 1⁄4 ðεk − n(2)1 sin(2) θ1Þ εk ; (8)...


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Journal ArticleDOI
Abstract: A new method of exciting nonradiative surface plasma waves (SPW) on smooth surfaces, causing also a new phenomena in total reflexion, is described. Since the phase velocity of the SPW at a metal-vacuum surface is smaller than the velocity of light in vacuum, these waves cannot be excited by light striking the surface, provided that this is perfectly smooth. However, if a prism is brought near to the metal vacuum-interface, the SPW can be excited optically by the evanescent wave present in total reflection. The excitation is seen as a strong decrease in reflection for the transverse magnetic light and for a special angle of incidence. The method allows of an accurate evaluation of the dispersion of these waves. The experimental results on a silver-vacuum surface are compared with the theory of metal optics and are found to agree within the errors of the optical constants.

2,501 citations

Journal ArticleDOI
Abstract: There are two modes of surface plasma waves: 1) Non-radiative modes with phase velocities Cü/k smaller than the velocity of light c. They cannot decay into photons in general. 2) Radiative modes with (o/k > c which couple directly with photons 1. The following paper is concerned with the excitation of these modes by light and their decay into photons. It has been shown that the radiative mode on thin silverand potassium-films can be excited by light and that the mode reradiates light almost into all directions with an intensity maximum at the plasma frequency cOp 2. It had been further observed that the non-radiative modes radiate under certain conditions if they are excited by electrons (grazing incidence of electrons on . a rough surface3 or at normal incidence on a grating 4) . The mechanism of this emission is in these cases always the same: The \"wave vector\" of the roughness of the surface or its irregularity changes the plasmon wave vector k so that a) in the case of the radiative mode light emission is found in directions in addition to that of reflexion and transmission, b) in the case of the non-radiative mode its wave vector is reduced so that the condition /c0, the wave vector of the inhomogeneous wave is (co/c) • Vsq' sin 0O (fq = 2.16 for quartz) and thus can excite a non radiative mode on the boundary of the prism for j/fq sin 0O > 1 or 90° > @o > 43°. If one vaporises a silver film directly on the quartz surface the inhomogeneous light wave penetrates into the silver film and excites a nonradiative mode on the boundary silver/air. The excitation will be highest for those frequencies which fulfill the dispersion relation of these surface plasmons.

2,484 citations

Journal ArticleDOI
Abstract: Surface plasmon resonance is a new optical technique in the field of chemical sensing. Under proper conditions the reflectivity of a thin metal film is extremely sensitive to optical variations in the medium on one side of it. This is due to the fact that surface plasmons are sensitive probes of the boundary conditions. The effect can be utilized in many ways. A description of how it can be used for gas detection is given, together with results from exploratory experiments with relevance to biosensing.

2,138 citations

Journal ArticleDOI
TL;DR: The data for the noble metals and Al, Pb, and W can be reasonably fit using the Drude model and it is shown that -epsilon1(omegas) = epsilon2(omega) approximately omega(2)(p)/(2omega( 2)(tau) at the damping frequency omega = omega(tau), where the plasma frequency is omega(p).
Abstract: Infrared optical constants collected from the literature are tabulated. The data for the noble metals and Al, Pb, and W can be reasonably fit using the Drude model. It is shown that -epsilon1(omega) = epsilon2(omega) approximately omega(2)(p)/(2omega(2)(tau)) at the damping frequency omega = omega(tau). Also -epsilon1(omega(tau)) approximately - (1/2) epsilon1(0), where the plasma frequency is omega(p).

1,906 citations

Journal ArticleDOI
25 Apr 2008-Langmuir
TL;DR: Gold nanoparticles of different shapes and sizes were dispersed into water-glycerol mixtures of varying volume ratios to investigate the response of their surface plasmon peaks to the refractive index of the surrounding medium.
Abstract: Gold nanoparticles of different shapes and sizes, including nanospheres, nanocubes, nanobranches, nanorods, and nanobipyramids, were dispersed into water-glycerol mixtures of varying volume ratios to investigate the response of their surface plasmon peaks to the refractive index of the surrounding medium. The refractive index sensitivities and figures of merit were found to be dependent on both the shape and the size of the Au nanoparticles. The index sensitivities generally increase as Au nanoparticles become elongated and their apexes become sharper. Au nanospheres exhibit the smallest refractive index sensitivity of 44 nm/RIU and Au nanobranches exhibit the largest index sensitivity of 703 nm/RIU. Au nanobipyramids possess the largest figures of merit, which increase from 1.7 to 4.5 as the aspect ratio is increased from 1.5 to 4.7.

990 citations