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Banshi Dhar Gupta - One of the best experts on this subject based on the ideXlab platform.

  • fabrication and characterization of a surface plasmon resonance based Fiber Optic Sensor using gel entrapment technique for the detection of low glucose concentration
    Sensors and Actuators B-chemical, 2013
    Co-Authors: Sarika Singh, Banshi Dhar Gupta
    Abstract:

    Abstract In this paper we report the fabrication and characterization of a surface plasmon resonance (SPR) based Fiber Optic Sensor, working on wavelength interrogation method, to measure the low glucose concentration (similar to the human blood) in aqueous fluid. The sensing probe is prepared by coating of films of silver and silicon on the Optical Fiber core followed by immobilization of enzyme (glucose oxidase) using gel entrapment method. Experimental results on SPR spectra show a blue shift in the resonance wavelength on increase in the concentration of the glucose in samples. Further, the sensitivity of the Sensor decreases as the concentration of the glucose increases whereas the detection accuracy is almost independent of the glucose concentration. In addition, for 80 mg/dL glucose concentration, the influence of pH of the sample on the performance of the Sensor has been studied in terms of sensitivity and detection accuracy. The results show that the optimum working pH range for the Sensor is around pH 7 (close to blood pH 7.4). The Sensor operates in the glucose concentration range of 0–260 mg/dL. Since the optimum performance and operating range of the Sensor fall in the physiological range of human blood glucose it may find application in biomedical sciences. The other advantages are high sensitivity, glucose selectivity, stability and short response time of the Sensor.

  • Surface plasmon resonance based Fiber Optic Sensor for the detection of low water content in ethanol
    Sensors & Actuators: B. Chemical, 2011
    Co-Authors: Sachin K Srivastava, Roli Verma, Banshi Dhar Gupta
    Abstract:

    A Fiber Optic Sensor utilizing surface plasmon resonance (SPR) has been fabricated for the detection of low content of water in ethanol. The Sensor utilizes spectral interrogation technique for operation. The resonance wavelength has been found to vary linearly with water content in the range 0–10% with sensitivity of 1.149nm per percentage of water. The results are in agreement with the refractive index variation of ethanol–water mixture. The Sensor has a water resolution of 0.145% which is better than the evanescent wave absorption Sensor reported for the similar study. The Sensor will find application in determining the low water content in ethanol which is used as a bio-fuel and in the field of medicine and organic chemistry.

  • surface plasmon resonance based Fiber Optic Sensor for the ir region using a conducting metal oxide film
    Journal of The Optical Society of America A-optics Image Science and Vision, 2010
    Co-Authors: R K Verma, Banshi Dhar Gupta
    Abstract:

    Theoretical modeling of a surface plasmon resonance (SPR) based Fiber Optic Sensor with a conducting metal oxide [indium tin oxide (ITO)] as the SPR active material is proposed. The theoretical analysis reveals that the proposed sensing probe can be utilized for sensing in the IR region, where most of the gases show their absorption regime. Comparison of sensitivity predicts that an ITO-layer-coated SPR-based Fiber Optic Sensor is about 60% more sensitive than a gold-coated Fiber Optic Sensor. The physical reasons behind sensitivity enhancement are provided. Apart from this, various advantageous features of the ITO over the noble metals, silver and gold, are addressed.

  • surface plasmon resonance based tapered Fiber Optic Sensor with different taper profiles
    Optics Communications, 2008
    Co-Authors: R K Verma, Anuj K Sharma, Banshi Dhar Gupta
    Abstract:

    Abstract A theoretical model for surface plasmon resonance (SPR) based tapered Fiber Optic Sensor is proposed with three different taper profiles, namely, linear, parabolic, and exponential-linear. The effect of taper ratio and taper profiles on the Sensor’s performance is studied in detail and the design considerations for significantly enhanced sensitivity are reported. The study shows that the exponential-linear taper profile with high taper ratio provides the best performance. The physical reasons behind sensitivity enhancement due to taper ratio and taper profile are given, wherever required.

  • Surface plasmon resonance based Fiber-Optic Sensor for the detection of pesticide
    Sensors and Actuators B: Chemical, 2007
    Co-Authors: Sudham Chand, Banshi Dhar Gupta
    Abstract:

    Fabrication and characterization of a surface plasmon resonance based Fiber-Optic Sensor for the detection of organophosphate pesticide, chlorphyrifos, have been reported. The probe is prepared by immobilizing acetylcholinesterase (AChE) enzyme on the silver coated core of a plastic-cladded silica (PCS) Fiber. The detection is based on the principle of competitive binding of the pesticide (acting as inhibitor) for the substrate (acetlythiocholine iodide) to the enzyme AChE. The spectral interrogation method has been used to characterize the Sensor. It has been observed that the SPR wavelength decreases with the increase in the concentration of the pesticide for the fixed concentration of substrate in the fluid around the probe. Further, the effect of the concentration of the substrate in the fluid on the resonance wavelength has been studied. The sensitivity, detection accuracy, reproducibility and stability of the Sensor have been also determined. It has been found that the sensitivity decreases with the increase in the concentration of the pesticide while reverse is the case for detection accuracy.

Chuji Wang - One of the best experts on this subject based on the ideXlab platform.

  • Fiber Loop Ringdown — a Time-Domain Sensing Technique for Multi-Function Fiber Optic Sensor Platforms: Current Status and Design Perspectives
    Sensors, 2009
    Co-Authors: Chuji Wang
    Abstract:

    Fiber loop ringdown (FLRD) utilizes an inexpensive telecommunications light source, a photodiode, and a section of single-mode Fiber to form a uniform Fiber Optic Sensor platform for sensing various quantities, such as pressure, temperature, strain, refractive index, chemical species, biological cells, and small volume of fluids. In FLRD, Optical losses of a light pulse in a Fiber loop induced by changes in a quantity are measured by the light decay time constants. FLRD measures time to detect a quantity; thus, FLRD is referred to as a time-domain sensing technique. FLRD Sensors have near real-time response, multi-pass enhanced high-sensitivity, and relatively low cost (i.e., without using an Optical spectral analyzer). During the last eight years since the introduction of the original form of Fiber ringdown spectroscopy, there has been increasing interest in the FLRD technique in Fiber Optic Sensor developments, and new application potential is being explored. This paper first discusses the challenging issues in development of multi-function, Fiber Optic Sensors or Sensor networks using current Fiber Optic Sensor sensing schemes, and then gives a review on current Fiber Optic Sensor development using FLRD technique. Finally, design perspectives on new generation, multi-function, Fiber Optic Sensor platforms using FLRD technique are particularly presented.

  • Fiber loop ringdown - A time-domain sensing technique for multi-function Fiber Optic Sensor platforms: Current status and design perspectives
    Sensors, 2009
    Co-Authors: Chuji Wang
    Abstract:

    Fiber loop ringdown (FLRD) utilizes an inexpensive telecommunications light source, a photodiode, and a section of single-mode Fiber to form a uniform Fiber Optic Sensor platform for sensing various quantities, such as pressure, temperature, strain, refractive index, chemical species, biological cells, and small volume of fluids. In FLRD, Optical losses of a light pulse in a Fiber loop induced by changes in a quantity are measured by the light decay time constants. FLRD measures time to detect a quantity; thus, FLRD is referred to as a time-domain sensing technique. FLRD Sensors have near real-time response, multi-pass enhanced high-sensitivity, and relatively low cost (i.e., without using an Optical spectral analyzer). During the last eight years since the introduction of the original form of Fiber ringdown spectroscopy, there has been increasing interest in the FLRD technique in Fiber Optic Sensor developments, and new application potential is being explored. This paper first discusses the challenging issues in development of multi-function, Fiber Optic Sensors or Sensor networks using current Fiber Optic Sensor sensing schemes, and then gives a review on current Fiber Optic Sensor development using FLRD technique. Finally, design perspectives on new generation, multi-function, Fiber Optic Sensor platforms using FLRD technique are particularly presented.

Bernadette Tse Sum Bui - One of the best experts on this subject based on the ideXlab platform.

  • A disposable evanescent wave Fiber Optic Sensor coated with a molecularly imprinted polymer as a selective fluorescence probe
    Biosensors and Bioelectronics, 2015
    Co-Authors: Xuan Anh Ton, Paolo Bonomi, Victor Acha, Bernadette Tse Sum Bui
    Abstract:

    We have developed a disposable evanescent wave Fiber Optic Sensor by coating a molecularly imprinted polymer (MIP) containing a fluorescent signaling group on a 4-cm long polystyrene Optical waveguide. The MIP is composed of a naphthalimide-based fluorescent monomer, which shows fluorescence enhancement upon binding with carboxyl-containing molecules. The herbicide 2,4-dichlorophenoxyacetic acid and the mycotoxin citrinin were used as model analytes. The coating of the MIP was either performed ex-situ, by dip-coating the Fiber with MIP particles synthesized beforehand, or in-situ by evanescent-wave photopolymerization on the Fiber. The sensing element was interrogated with a Fiber-coupled spectrofluorimeter. The Fiber Optic Sensor detects targets in the low nM range and exhibits specific and selective recognition over structural analogs and non-related carboxyl-containing molecules. This technology can be extended to other carboxyl-containing analytes, and to a broader spectrum of targets using different fluorescent monomers.

  • A molecularly imprinted polymer-based evanescent wave Fiber Optic Sensor for the detection of basic red 9 dye
    Sensors and Actuators B: Chemical, 2015
    Co-Authors: Marcos V. Foguel, Maria Valnice B. Zanoni, Maria Del Pilar T. Sotomayor, Xuan Anh Ton, Karsten Haupt, Bernadette Tse Sum Bui
    Abstract:

    A cheap and robust method for the detection and quantification of textile dyes is the use of biomimetic Sensors with Optical transduction, employing a molecularly imprinted polymer (MIP) as the recognition element. This paper presents the optimization of a MIP for the dye, basic red 9 (BR9) and the immobilization of these polymers on a disposable 4-cm long polystyrene Optical waveguide for the development of an evanescent wave Fiber Optic Sensor aimed at the determination and quantification of this dye in different matrices and industrial effluents. MIPs were synthesized using 2-acrylamido-2-methyl-1-propanesulfonic acid and ethylene glycol dimethacrylate, as functional monomer and cross-linker, respectively. The polymer was then immobilized on the waveguide by dip-coating the Fiber in the polymer suspension. The sensing element was interrogated with a Fiber-coupled spectrophotometer. BR9 could be detected in the low ?M range, thus making it a promising device for determining this compound in textile effluents.

Vivek Sajal - One of the best experts on this subject based on the ideXlab platform.

  • sensitivity enhancement of a surface plasmon resonance based Fiber Optic Sensor using zno thin film a theoretical study
    Sensors and Actuators B-chemical, 2015
    Co-Authors: Sarika Shukla, Navneet K Sharma, Vivek Sajal
    Abstract:

    Abstract A surface plasmon resonance (SPR) based Fiber Optic Sensor with bi layers of metal–ZnO is proposed and theoretically studied. Three metals: gold (Au), silver (Ag) and copper (Cu) have been exercised in the study. The top ZnO layer is shown to protect the metallic layer from oxidation and to enhance the sensitivity of the SPR Sensor. Besides, increase in thickness of Au/Ag/Cu layer increases the sensitivity of SPR Sensor for all thicknesses of ZnO layers. For a fixed thickness of ZnO layer, the sensitivity of Sensor is larger for Au layer than that of Ag/Cu layer. Sensitivity also increases with increase in ZnO layer thickness for all thicknesses of Au/Ag/Cu layers. The SPR Sensor based on bi layers of 40 nm Au–15 nm ZnO demonstrates the maximum sensitivity of 3161 nm/RIU.

Sudham Chand - One of the best experts on this subject based on the ideXlab platform.

  • Surface plasmon resonance based Fiber-Optic Sensor for the detection of pesticide
    Sensors and Actuators B: Chemical, 2007
    Co-Authors: Sudham Chand, Banshi Dhar Gupta
    Abstract:

    Fabrication and characterization of a surface plasmon resonance based Fiber-Optic Sensor for the detection of organophosphate pesticide, chlorphyrifos, have been reported. The probe is prepared by immobilizing acetylcholinesterase (AChE) enzyme on the silver coated core of a plastic-cladded silica (PCS) Fiber. The detection is based on the principle of competitive binding of the pesticide (acting as inhibitor) for the substrate (acetlythiocholine iodide) to the enzyme AChE. The spectral interrogation method has been used to characterize the Sensor. It has been observed that the SPR wavelength decreases with the increase in the concentration of the pesticide for the fixed concentration of substrate in the fluid around the probe. Further, the effect of the concentration of the substrate in the fluid on the resonance wavelength has been studied. The sensitivity, detection accuracy, reproducibility and stability of the Sensor have been also determined. It has been found that the sensitivity decreases with the increase in the concentration of the pesticide while reverse is the case for detection accuracy.