Browsing by Author "Subanya S"

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A COMPARATIVE STUDY ON THE PERFORMANCE OF SPR BASED CONVENTIONAL AND NANO-PLASMONIC FIBER OPTIC SENSORS
(Bannari Amman Institute of Technology, 2017-08) Subanya S; Pavithra D; Rajesh K B
The technique of Surface plasmon resonance has become a highly influential method for its chemical, bio-chemical and gas sensing applications due to its compactness, flexibility and reliability. A detailed analysis on the performance parameters of SPR based fiber optic sensors having different bimetallic configurations is performed. Two different sensor structures are considered for the study - One having the arrangement consisting of thin layers of Au/Ag with Pd and the other having an alloy layer formed of Au/Ag and Pd nanoparticles. The thickness of the metal layer, its dielectric constants and the thickness, length and refractive index of the sensing layer is properly chosen and the sensitivity evaluation is done. The attenuated total internal reflection method along with Krestchmann configuration has been used to analyze the sensor parameters. The effects of the metal structures considered and its thicknesses on the transmitted spectrum of the proposed sensor is analysed and the best configuration is predicted. The proposed optical model may find its application as a gas sensor.
EFFECT OF GRAPHENE LAYER ON CHALCOGENIDE GLASS PRISM BASED SPR SENSOR
(Chikkanna Government Arts College, Tirupur, 2017-01-19) Venkateswari P; Subanya S; Rajesh K B
It is observed that plasmonic structure based on (chalcogenide) sulfide glass Ge20Ga5Sb10S65 commonly known as 2S2G allows for a wide range of sensing applications in the infrared wavelength region. In this paper, we theoretically presents an improved sensitive surface plasmon resonance bio sensor using graphene layers on 2S2G prism. The light reflection coupled into a spr mode propagating along metal graphene interface on the 2S2G prism is calculated and compared to a conventional silver based spr bio sensor. This enhancement is due to the pi-stacking interaction between carbon based hexagonal structure of graphene and carbon based ring biomolecules which increases biomolecular adsorption in the graphene layer.
EFFECT OF GRAPHENE ON THE PERFORMANCE OF SPR BASED FIBER OPTIC SENSOR
(Chikkanna Government Arts College, Tirupur, 2017-01-19) Santhiya Devi S; Subanya S; Kasthuri R; Rajesh K B
Conventional SPR sensors makes use of a dielectric metal configuration which finds application in the visible and near infrared region. However, it is least sensitive to mid and far infrared region. To overcome the shortcoming, graphene ribbon array are employed. Due to its unique physical, chemical and optical properties, graphene finds its application in various photonic devices and sensors. Theoretical simulation on the effect of graphene on the performance of spr based fiber optic sensor has been done. The attenuated total internal reflection method along with Krestchmann configuration has been used to analyze the sensor parameters. The influence of the number of graphene layers on the various choice of metal having particular thickness was felt in the sensor performance. The proposed optical model suits best as a bio-sensor
EXCITATION OF SURFACE PLASMON ON GRAPHENE COATED METAL LAYER BY RADIALLY POLARIZED BESSEL GAUSSIAN BEAM
(Bharathiar University, 2013-02-01) Veerabagu Suresh N; Lavanya M; Subanya S; Rajesh K B
Rapid advance of nano structuring technologies offers new possibilities for flexible and low-cost fabrication of plasmonic components and devices. When a radially polarized Bessel Gaussian beam is focused onto a metal-dielectric interface, the entire beam is TM polarized with respect to the interface. Consequently surface plasmons can be excited at all directions. These surface plasmons will propagate to the geometric center, constructively interfere with each other and generate a strongly focused evanescent non diffracting Bessel beam. In this paper, we analysed the excitation of surface plasmon polaritons SPP by focusing a radially polarised Bessel Gaussian beam on a Chalcogenide glass plate and a gold layer coated with a thin layer of graphene. The graphene layer is used to enhance the adsorption of biomolecules. However the change in the intensity distribution of the generated surface plasmon owing to the presence of graphene layer is very important and is analysed numerically in this work.
GRAPHENE BASED SPR BIOSENSOR FOR SENSITIVITY EVALUATION
(Chikkanna Govt. Arts College, Tiruppur, 2019-02-01) Kaviyarasi K; Abiramavalli T; Subanya S; Rajesh K B
In the recent years, the application of spr based fibre optic sensors have progressed very rapidly. Due to the increase in diseases and diagnotics, the urge for bio sensing applications have drawn the attention of researchers. A detailed numerical analysis on the performance parameter of an optical fibre based SPR sensors with Graphene layers over four different metals Pt/Au/Ag/Cu have been studied. Graphene not only helps in the adsorption of biomolecules due to pi-pi stacking interaction but also prevents metal oxidation. The thickness of the metal layer, its dielectric constants and the thickness, length and refractive index of the sensing layer is properly chosen and the sensitivity evaluation is done. The inclusion of Graphene layer is found to improve the sensitivity of the sensor. The attenuated total internal reflection method along with Krestchmann configuration has been employed for the evaluation. The effects of the metal structures considered and its thicknesses on the transmitted spectrum of the proposed sensor is analysed. Amongst the various chosen combinations, the proposed optimized Platinum Graphene coated SPR sensor demonstrates higher sensitivity than the previously reported spr sensors. The proposed configuration will surely be a promising candidate for high performance bio-sensing applications.
HIGH PERFORMANCE SPR BASED FIBER OPTIC SENSORS USING MXENE
(Chikkanna Govt. Arts College, Tiruppur, 2020-03-05) Balamurugeshwari A; Nivethitha P.V; Subanya S; Rajesh K.B
In the last few decades, Surface Plasmon Resonance based optical sensors has created a niche for itself in the field of bio, chemical and gas sensing applications due to their surprising superior characteristics such as its high sensitivity, reliability, real time sensing ability, compactness and flexibility. Recently a new family of 2d transition metal carbide/ nitride materials known as MXene has drawn increased attention due to their exceptional properties like excellent thermal stability, easily tunable structure, large interlying surface, high electrical conductivity and large surface area. A detailed analysis on the performance parameters of SPR based fiber optic sensors having a Four layer model - Core/metal/Mxene/Sensing medium is performed. Kretschmann configuration and the N layer matrix model has been employed for the performance study and a novel SPR sensor based on Au/Ag/Co/Ni with MXene layers is theoretically presented. The thickness of the metal layer, Mxene and the RI of the multi layers have been properly chosen. Enhanced sensitivity is observed in the MXene based Sensor compared to the bare metal based SPR sensor as well as the conventional metal film sensors. The other sensor parameters such as the Quality Factor, Detection Accuracy, Signal to Noise ratio has also shown desired values. Owing to their unique properties, MXene has demonstrated promising nature for various applications such as energy storage, chemical, photo and electrocatalyst, photothermal therapy, gas sensing etc.
INVESTIGATION ON THE PERFORMANCE OF THE PRISM BASED SPR SENSOR WITH COMPOSITE OF INDIUM NITRATE AND GOLD
(Journal of Environmental Nanotechnology, 2014-12) Veerabagu Suresh N; Agalya M; Subanya S; Lavanya M; Rajesh K B
In this paper, we theoretically studied the role of the prism material in sensor design of SPR-based sensor. We analysed the performance of three prisms of different refractive indices coated with composites of Indium tin oxide and gold with different thickness values. We studied the reflection spectra under the angular interrogation mode and the performance are evaluated by employing two main parameters such as sensitivity and Full width Half Maximum (FWHM) of resonance curve. It is found that 10% of ITO hosted in metal matrix of gold gives the highest shift (8.14Ëš) in resonance angle and least FWHM (5.15Ëš) of the resonance curve for the film thickness of 50nm for the prism of np=1.456.
NUMERICAL SIMULATION OF BI-CASCADED FIBRE OPTIC SURFACE PLASMON RESONANCE SENSORS
(Bharathidasan University, 2016-03-18) Pavithra D; Subanya S; Kasthuri R
In the present work, numerical simulation of a bi-cascaded surface plasmon resonance based fibre optic sensor using various noble metals has been carried out. The attenuated total internal reflection method along with Krestchmann configuration has been used to analyze the sensor. The thickness of the metal layer, its dielectric constants and the thickness, length and refractive index of the sensing layer is properly chosen and the sensitivity evaluation is done and the various sensor parameters have been optimized. The proposed sensor is bi-cascaded ie., it can simultaneously detect two kinds of substances. It provides reasonable values of performance parameters and hence finds application as a good chemical/gas/biosensor.
NUMERICAL SIMULATION OF SPR BASED FIBER OPTIC GAS SENSOR USING AN ALTERNATING DIELECTRIC MULTILAYER
(Chikkanna Government Arts College, Tirupur, 2017-01-19) Kasthuri R; Sathiyapriya D; Subanya S; Rajesh K B
The technique of Surface plasmon resonance has become a highly influential method for its chemical and bio-chemical sensor applications due to its compactness and reliability. Surface plasmon resonance based fiber optic sensor with an alternating dielectric multilayer system is theoretically studied in detail. The dielectric system is constructed with alternate silica and titanium oxide layers sandwiched between the metal of study. Besides prevention of metallic layer from oxidation, it also enhances the sensitivity, tunability of the resonance wavelength region, bio-compatibility and capability of gas sensing. The effect of various design attributes on the sensitivity and detection accuracy of the sensor is studied for three different metal layers.. Based on the study, a new optical model of a fiber optic spr gas sensor is proposed.
NUMERICAL SIMULATION ON THE PERFORMANCE OF SPR BASED FIBER OPTIC SENSOR USING NANOCOMPOSITES
(Chikkanna Govt. Arts College, Tiruppur, 2019-02-01) Abiramavalli T; Kaviyarasi K; Subanya S; Rajesh K B
In the last few decades, Surface Plasmon Resonance technique has become highly influential for its chemical, bio-chemical and gas sensing applications due to its compactness, flexibility and reliability. Transparent conducting oxide like In2O3 are of immense interest due to their good electrical conductivity property and high transparency in the visible and infra red region. A study on the performance of spr based fiber optic sensor with nanocomposites has been carried out numerically and investigated. Nanocomposites comprising of Co and Ni nanoparticles with their varying volume fractions embedded in the host dielectric matrices of Indium Oxide are considered for the study. The metal nanoparticles exhibit tremendous optical properties originating from the surface plasmons and hence show better sensing performance than materials in the macro or large scales. By varying the thickness of the nanocomposite for various volume fractions, the performance parameters such as FWHM, sensitivity and Q-factor of the sensor were studied and analyzed. The sensitivity of Ni/In2O3 nanocomposites based sensor shows better performance for all thicknesses with any volume fraction compared to Co/In2O3 nanocomposites. It is observed that the sensitivity of the sensor increases with increase in both thickness of the nanocomposites and the volume fraction of metal nanoparticles. The usage of Co and Ni in the place of noble metals has curtailed the cost of the spr sensor.
PERFORMANCE ANALYSIS OF GRAPHENE BASED SPR SENSORS FOR BIO SENSING APPLICATIONS
(IIT Delhi, 2018-12-13) Subanya S; Rajesh K B
For the past three and more decades, the application of spr based fibre optic sensors have progressed very rapidly. Due to the increase in diseases and diagnotics, the struggle for existence of human life increases and hence the urge for bio sensing applications have drawn the attention of researchers. Numerical analysis on the performance parameter of an optical fibre based SPR sensors with Graphene layers over four different nobel metals have been studied. Graphene which is a biological resistance element not only helps in the adsorption of biomolecules due to pi-pi stacking interaction but also prevents metal oxidation. The paramters of the sensor such as the thickness of the metal layer, its dielectric constants, length and refractive index of the sensing layer is properly chosen and the sensitivity evaluation is done. The presence of the Graphene layer is found to enhance the sensitivity of the sensor. The attenuated total internal reflection method along with Krestchmann configuration has been employed for the evaluation. The effects of the metal structures considered and its thicknesses on the transmitted spectrum of the proposed sensor is analysed. Amongst the various chosen combinations, the proposed optimized Platinum Graphene coated SPR sensor demonstrates higher sensitivity than the previously reported spr sensors. The proposed configuration will surely be a promising candidate for high performance bio-sensing applications.
SENSITIVITY ENHANCEMENT OF A SURFACE PLASMON RESONANCE BASED FIBER OPTIC REFRACTIVE INDEX SENSOR USING UTILIZING AN ADDITIONAL LAYER OF OXIDE
(Chikkanna Government Arts College, Tirupur, 2017-01-19) Alagu Vibisha G; Subanya S; Rajesh K B
Surface Plasmon Resonance base fiber optic sensor with bi layers of Pt- TiO2 is theoretically analysed. The Pt layer over TiO2 layer has been shown to improve the sensitivity of SPR sensor, The sensitivity of the proposed sensor enhances linearly with the increase in the refractive index of the sensing medium for all thicknesses of Pt layers, with increase in TiO2 layer thickness. SPR based fiber optic sensor with bi layers of 50 nm Pt-200nm TiO2 displays the highest sensitivity of 18000 nm/RIU.
SENSITIVITY ENHANCEMENT OF SPR SENSOR USING NI/ZNO NANOCOMPOSITE ASSISTED WITH GRAPHENE
(Springer US, 2021-11) Maheswari P; Subanya S; Nisha A; Ravi V; Rajesh KB; Rajan, Jha
In this paper the performance of surface plasmon resonance (SPR) biosensor in modified kretchmann configuration utilizing nanocomposite layer consisting of nickel and ZnO as plasmonic material is analyzed numerically using N-layered transfer matrix method. The performance parameters of proposed sensor are investigated in terms of sensitivity (S), detection accuracy (DA) and quality factor (QF) at the operating wavelength of 633 nm. Parameters such as the influence of refractive index of the coupling prism, the thickness of the nanocomposite layer, the constituent components of the nanocomposite layer and the number of the graphene layers over the nanocomposite layer are investigated and the optimal values are identified to achieve maximum sensitivity. The numerical results shows that upon suitable optimization of the above parameters, the proposed SPR sensor is found to exhibits sensitivity as high as 378.34°/RIU with quality factor (QF) as 39.78/RIU. Compared with existing similar type of SPR sensors, the proposed sensor exhibits higher sensitivity, lower FWHM and better quality factor which would make our design to have more applications in the field of biosensor.
SPR BASED BIO SENSORS USING BLACK PHOSPHORUS - A BOON TO BIOMEDICAL APPLICATIONS
(Chikkanna Govt. Arts College, Tiruppur, 2020-03-05) Deepapriya G.S; Nivethitha P.V; Subanya S; Rajesh K.B
The recent attention of plasmonic research has turned its focus towards the field of biomedical applications, due to the excitingly appreciable optical, electronic, chemical, thermal and mechanical properties of the 2D materials. Though these materials exhibited good sensing performance, there existed certain shortcomings like the lack of bandgap in graphene, low carrier mobility of TMDCs which hindered their usage in bio-sensing applications leading to the search for a new 2D material with desirable properties for improved sensor parameters. Black phosphorus (BP), an emerging two-dimensional (2D) material has appreciably unique physical, chemical, electronic and optical properties like direct band gap, smaller work function, high charge carrier mobility, better binding of molecules on sensor surface, high surface to volume ratio, above all its biodegradability and negligible toxicity in the biological environment which keeps it par from the other available 2D materials. This has aroused more and more research interest on the biomedical applications of BP. A detailed numerical analysis on the performance parameter of an optical fibre based SPR sensors with BP layers over spr active metals Au/Ag/Co/Ni/Cu have been studied. The parameters such as the thickness of the metal and the BP layer, its dielectric constants and refractive index of the sensing layer is properly chosen and sensitivity evaluation is performed in terms of its FWHM, Sensitivity, Quality Factor and Detection Accuracy. A noticeably high improvement is witnessed in Sensitivity and the other parameters due to the presence of the BP layers. The reason for the enhancement in sensitivity is due to the better binding of biomolecules. The attenuated total internal reflection method along with Krestchmann configuration has been employed for the evaluation of parameters. The effects of the metal structures considered and its thicknesses on the transmitted spectrum of the proposed sensor is analysed by transfer matrix method. The proposed configuration will surely be a promising candidate for high performance bio-sensing applications.
STRUCTURAL AND OPTICAL CHARACTERIZATION OF PURE AND STARCH-CAPPED ZNO QUANTUM DOTS AND THEIR PHOTOCATALYTIC ACTIVITY
(Springer Berlin Heidelberg, 2015-02) Vidhya K; Saravanan M; Bhoopathi G; Devarajan VP; Subanya S
Among the different types of metal oxides, zinc oxide (ZnO) is a most commonly used metal oxide in a broad variety of applications. In the present investigation, a modified green synthesis route was used to synthesize pure and starch-capped ZnO (ZnO/starch) quantum dots (QDs) and studied their structural and optical characteristics. In this study, hexagonal crystal structure was observed in both pure and ZnO/starch QDs using X-ray diffraction technique. A spherical-shaped surface morphology was found with the size of 5–10 nm using transmission electron microscope technique. The interaction between ZnO QDs and starch molecules was proved via Fourier infra-red spectrometer technique. On the other hand, their fluorescence behaviors were investigated using photoluminescence technique, in that the ZnO/starch QDs showed an
SURFACE PLASMON RESONANCE BASED FIBRE OPTIC SENSORS FOR SENSITIVITY EVALUATION
(PSGR Krishnammal College for Women, 2019-01-21) Abiramavalli T; Kaviyarasi K; Subanya S; Rajesh K B
The technique of Surface plasmon resonance has become a highly influential method for its chemical, bio-chemical and gas sensing applications due to its compactness, flexibility and reliability. Recent reports convey that Surface Plasmon Resonance has also been involved in the energy conversion of solar energy harvesting with the application of metamaterials. Surface Plasmon resonance imaging involves the detection of material properties like density, temperature, concentration, refractive index measurement under various environmental conditions. A detailed numerical analysis on the performance parameter of an optical fibre based SPR sensors with Graphene layers over four different metals Pt/Au/Ag/Cu have been studied. The inclusion of Graphene layer is found to improve the sensitivity of the sensor. The thickness of the metal layer, its dielectric constants and the thickness, length and refractive index of the sensing layer is properly chosen and the sensitivity evaluation is done. The attenuated total internal reflection method along with Krestchmann configuration has been employed for the evaluation. The effects of the metal structures considered and its thicknesses on the transmitted spectrum of the proposed sensor is analysed. Amongst the various chosen combinations, the proposed optimized Platinum Graphene coated SPR sensor shows greater sensitivity than the previously reported spr sensors.
THEORETICAL STUDY ON SURFACE PLASMON RESONANCE BASED FIBER OPTIC SENSORS USING PLATINUM -TMDC BILAYERS
(VIT , Chennai, 2020-01-08) Subanya S; Rajesh K.B
A surface plasmon resonance based fiber optic sensor with Platinum (Pt) coated with Transition Metal Dichalcogenides (TMDCs) - Molybdenum disulfide (MoS2), Molybdenum diselenide (MoSe2), Tungsten disulfide (WS2) and Tungsten diselenide (WSe2) is theoretically studied and analyzed (taking a metal and a TMDC at a time). The attenuated total internal reflection method along with Krestchmann configuration has been used to analyze the performance of the sensor. The sensitivity of the sensor increases linearly with increase in refractive index of the sensing medium for all thickness of Co and Ni (from 20 nm to 60 nm) and for increase in the number of TMDC layer. SPR sensor with 60 nm Platinum and five layers of WS2 exhibits highest sensitivity of 4798.4 nm/RIU. The utilization of Pt instead of Noble metals like gold and silver improves the performance of the sensor. The proposed WS2 assisted sensor will surely be a promising candidate for high performance sensing applications.
THEORETICAL ANALYSIS OF SPR CHARACTERISTICS OF IRIDIUM
(Chikkanna Government Arts College, Tirupur, 2017-01-19) Mohanapriya S; Subanya S; Kasthuri R; Rajesh K B
The technology and applications of optical fiber have progressed very rapidly in the recent years. A detailed theoretical analysis on the performance of single and bimetal iridium layer coated on a core of an optical fiber. By varying the structure of the iridium as thin film, nanoparticle and grating, the performance of the spr based fiber optic sensor is studied and compared in detail. To study the performance of the sensor, we calculated the sensitivity, Reflection coefficient, Q factor and FWHM using Iridium with other spr active metals. Interestingly, as the thickness of the iridium layer increases, dominance of inverted surface plasmon resonance character of iridium was also observed and analyzed. At specific conditions, iridium exhibits normal as well as inverted spr characteristics. The proposed sensor finds application in various fields.
THEORETICAL ANALYSIS ON THE PERFORMANCE OF SPR BASED FIBER OPTIC SENSORS USING METAL LAYERS WITH BIMETALLIC NANOCOMPOSITES
(Bharathidasan University, 2016-03-18) Anusha V; Subanya S; Kasthuri R
We theoretically studied the performance of various noble metals with Au nanocomposites. A thin nanocomposite layer of the required composition is coated over the core. By varying the thickness of the nanocomposite layer, the performance parameters of the proposed sensor were studied and analyzed. The thickness of the layer(25nm) is optimized for various proportion of x. The overall performance of the sensor is studied in terms of FWHM , sensitivity, Q factor and SNR ratio. On comparing the results obtained, the best nanocomposite suitable for sensor applications has been predicted.
THEORETICAL INVESTIGATION OF BI-CASCADED FIBRE OPTIC SURFACE PLASMON RESONANCE SENSORS
(Chikkanna Government Arts College, Tirupur, 2017-01-19) Pavithra D; Subanya S; Kasthuri R; Rajesh K B
In the present work, a bi-cascaded surface plasmon resonance based fibre optic sensor using various noble metals has been theoretically studied. The attenuated total internal reflection method along with Krestchmann configuration has been used to analyze the sensor. The proposed sensor is bi-cascaded ie., it can simultaneously detect two kinds of chemical substances by using wavelength division multiplexing technology. The sensor 1 is coated with a single layer of Au/Ag thin film of optimised thickness 50nm and the sensor 2 is coated with Pd/Pt/Ir thin films of optimised thickness 10nm The thickness of the metal layer, its dielectric constants and the thickness, length and refractive index of the sensing layer is properly chosen and the sensitivity evaluation is done. The effects of the metals considered and its thicknesses on the transmitted spectrum of the bi-cascaded sensor have been discussed and the calculations show that the cascaded sensor produces two resonance dips with a greater difference. It provides reasonable values of performance parameters and hence finds application as a good chemical/gas/biosensor.