The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
Andres D. Campiglia - One of the best experts on this subject based on the ideXlab platform.
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Gold nanorods for surface Plasmon resonance detection of mercury (II) in flow injection analysis.
Talanta, 2014Co-Authors: Khang Trieu, Emily C. Heider, Scott C. Brooks, Fernando Barbosa, Andres D. CampigliaAbstract:Abstract This article investigates the flow injection analysis of mercury (II) ions in tap water Samples via surface Plasmon resonance detection. Quantitative analysis of mercury (II) is based on the chemical interaction of metallic mercury with gold nanorods immobilized on a glass substrate. A new flow cell design is presented with the ability to accommodate the detecting substrate in the Sample Compartment of commercial spectrometers. Two alternatives are here considered for mercury (II) detection, namely stop-flow and continuous flow injection analysis modes. The best limit of detection (2.4 ng mL −1 ) was obtained with the continuous flow injection analysis approach. The accurate determination of mercury (II) ions in Samples of unknown composition is demonstrated with a fortified tap water Sample.
Marco Daturi - One of the best experts on this subject based on the ideXlab platform.
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Coupling a Rapid-Scan FT-IR Spectrometer with Quantum Cascade Lasers within a Single Setup: An Easy Way to Reach Microsecond Time Resolution without Losing Spectral Information.
Analytical chemistry, 2019Co-Authors: Josefine Schnee, Philippe Bazin, Benoit Barviau, Frédéric Grisch, Bruno J. Beccard, Marco DaturiAbstract:For the first time, a standard rapid-scan Fourier-transform infrared (FT-IR) spectrometer was coupled with quantum cascade lasers (QCLs) tunable within the 1876–905 cm–1 spectral range, within one single setup, by keeping one single Sample Compartment. The aim was to extend the time resolution of absorption measurements by several orders of magnitude thanks to the fast pulsed QCL technology without losing the spectral information provided by standard FT-IR spectroscopy, both probing the same Sample. By slightly modifying the optical bench arrangement, the spectrometer now enables a fast and easy switch between the standard FT-IR mode, used for classical broadband scans from 6000 to 650 cm–1, and the new QCL-irradiation mode, used for ultrafast recording at specific wavenumbers (the two diagnostics have superimposed beam paths). So, one can study a Sample (in condensed or gaseous state) during a physical or chemical transformation first as a whole in a broadband configuration and then immediately switch to...
Eric Bakker - One of the best experts on this subject based on the ideXlab platform.
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Electrogenerated Chemiluminescence for Chronopotentiometric Sensors
Analytical chemistry, 2019Co-Authors: Wenyue Gao, Stéphane Jeanneret, Dajing Yuan, Thomas Cherubini, Lu Wang, Xiaojiang Xie, Eric BakkerAbstract:We introduce here a general strategy to read out chronopotentiometric sensors by electrogenerated chemiluminescence (ECL). The potentials generated in chronopotentiometry in a Sample Compartment are used to control the ECL in a separate detection Compartment. A three-electrode cell is used to monitor the concentration changes of the analyte, while the luminol–H2O2 system is responsible for ECL. The principle was shown to be feasible by theoretical simulations, indicating that the Sampled times at a chosen potential, rather than traditional transition times, similarly give linear behavior between concentration and the square root of Sampled time. With the help of a voltage adapter, the experimental combination between chronopotentiometry and ECL was successfully implemented. As an initial proof of concept, the ferro/ferricyanide redox couple was investigated. The square root of time giving maximum light output changed linearly with ferrocyanide concentration in the range from 0.70 to 4.81 mM. The method wa...
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Electrogenerated Chemiluminescence for Chronopotentiometric Sensors
2019Co-Authors: Wenyue Gao, Dajing Yuan, Thomas Cherubini, Lu Wang, Xiaojiang Xie, Stéphane Jeanneret, Eric BakkerAbstract:We introduce here a general strategy to read out chronopotentiometric sensors by electrogenerated chemiluminescence (ECL). The potentials generated in chronopotentiometry in a Sample Compartment are used to control the ECL in a separate detection Compartment. A three-electrode cell is used to monitor the concentration changes of the analyte, while the luminol–H2O2 system is responsible for ECL. The principle was shown to be feasible by theoretical simulations, indicating that the Sampled times at a chosen potential, rather than traditional transition times, similarly give linear behavior between concentration and the square root of Sampled time. With the help of a voltage adapter, the experimental combination between chronopotentiometry and ECL was successfully implemented. As an initial proof of concept, the ferro/ferricyanide redox couple was investigated. The square root of time giving maximum light output changed linearly with ferrocyanide concentration in the range from 0.70 to 4.81 mM. The method was successfully applied to the visual detection of carbonate alkalinity from 0.06 to 0.62 mM using chronopotentiometry at an ionophore-based hydrogen ion-selective membrane electrode. The measurements of carbonate in real Samples including river water and commercial mineral water were successfully demonstrated
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Ionophore-based ion optodes without a reference ion: electrogenerated chemiluminescence for potentiometric sensors.
The Analyst, 2012Co-Authors: Gastón A. Crespo, Eric BakkerAbstract:We report here on an electrogenerated chemiluminescence (ECL) readout for potentiometric ion-sensors, thereby offering an optical sensor output without the need for a reference ion (typically the hydrogen ion) that inconveniences ionophore based optical sensor principles. The Compartment for ECL generation is physically separated from the Sample by a bridge, and no current flows through the Sample Compartment. Here, three different types of ion selective membranes (Ca(2+), Na(+) and K(+)) are read-out individually and sequentially with this methodology. The repeatabilities are found as 0.5 to 1% of integrated light output, which translates into a relative uncertainty in the activity measurement of about 10%. This uncertainty appears to originate primarily at the ECL generating gold electrode, not at the potentiometric sensor. Other analytical figures of merit such as measuring range, sensitivity, optimal applied potential for ECL generation, and ion selectivity are also described.
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Electrogenerated chemiluminescence triggered by electroseparation of Ru(bpy) 3 2+ across a supported liquid membrane
Chemical communications (Cambridge England), 2011Co-Authors: Gastón A. Crespo, Guenter Mistlberger, Eric BakkerAbstract:We demonstrate here for the first time the detection of electrogenerated chemiluminescence (ECL) upon selective, electrochemically triggered tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) transport across a supported liquid membrane doped with a lipophilic cation-exchanger. This approach allows one to separate the location of ECL generation from the Sample Compartment, thereby avoiding the contamination of the Sample with compounds necessary for ECL.
Khang Trieu - One of the best experts on this subject based on the ideXlab platform.
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Gold nanorods for surface Plasmon resonance detection of mercury (II) in flow injection analysis.
Talanta, 2014Co-Authors: Khang Trieu, Emily C. Heider, Scott C. Brooks, Fernando Barbosa, Andres D. CampigliaAbstract:Abstract This article investigates the flow injection analysis of mercury (II) ions in tap water Samples via surface Plasmon resonance detection. Quantitative analysis of mercury (II) is based on the chemical interaction of metallic mercury with gold nanorods immobilized on a glass substrate. A new flow cell design is presented with the ability to accommodate the detecting substrate in the Sample Compartment of commercial spectrometers. Two alternatives are here considered for mercury (II) detection, namely stop-flow and continuous flow injection analysis modes. The best limit of detection (2.4 ng mL −1 ) was obtained with the continuous flow injection analysis approach. The accurate determination of mercury (II) ions in Samples of unknown composition is demonstrated with a fortified tap water Sample.
Bertil Forslund - One of the best experts on this subject based on the ideXlab platform.
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Carbothermal synthesis of Aluminium Oxynitride (ALON) powder: Influence of starting materials and synthesis parameters
Journal of the European Ceramic Society, 1995Co-Authors: Jie Zheng, Bertil ForslundAbstract:Abstract Carbothermal synthesis of cubic aluminium oxynitride (ALON) have been performed in a graphite furnace at different temperatures (1700–1860 °C) and pressures (0.1–10 MPa). The products were characterized by XRD, SEM and elemental analyses, and the overall compositions were determined by reoxidation in air. The control of excess nitridation was a crucial task in the preparation of ALON. A two-step procedure, first annealing at about 1550 °C then at about 1800 °C, was found to be effective to this end. CO additions to the N2 gas stimulated ALON formation, but a pressure increase resulted in a lower nitridation rate. The particle size and morphology of ALON depended on raw material type and synthesis parameters such as temperature program, pressure, CO content in the N2 gas, and Sample Compartment type. Thermodynamic calculations in the Al-O-C-N system have been performed in order to explain the experimental results.
