The Experts below are selected from a list of 26379 Experts worldwide ranked by ideXlab platform
H Perrot - One of the best experts on this subject based on the ideXlab platform.
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Unveiling the ionic exchange mechanisms in vertically-oriented graphene nanosheet supercapacitor electrodes with electrochemical quartz crystal Microbalance and ac-electrogravimetry
Elsevier, 2018Co-Authors: D. Aradilla, H Perrot, G. Bidan, F. Billon, M. Delaunay, J.m. Gérard, O. SelAbstract:This work presents the first electrochemical quartz crystal Microbalance (EQCM) results for vertically-oriented graphene nanosheets (VOGNs) as supercapacitor electrodes. Conventional EQCM technique delivered primary insights on the ionic exchange mechanisms between VOGNs and organic electrolytes, showing a major contribution of anions. A more advanced electrogravimetric methodology, ac-electrogravimetry, was then used to access specific dynamic attributes for each species exchanged at the VOGN electrode surface. Accordingly, under the conditions of this study, anions were confirmed to be the major energy storage vector with high kinetic values and low transfer resistance while cations and free solvent molecules are given non-negligible supporting roles. Keywords: Supercapacitors, Microbalance, ac-electrogravimetry, Graphen
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sensitivity noise and resolution in qcm sensors in liquid media
IEEE Sensors Journal, 2005Co-Authors: L Rodriguezpardo, C Gabrielli, H Perrot, J F Rodriguez, R BrendelAbstract:The use of quartz-crystal oscillators as high-sensitivity Microbalance sensors is limited by the frequency noise present in the circuit. To characterize the behavior of the sensors, it is not enough to determine their experimental sensitivity, but, rather, it is essential to study the frequency fluctuations in order to establish the sensor resolution. This is fundamental in the case of oscillators for damping media, because the level of noise rises due to the strong decline of the quality factor of the resonator. In this paper, a comparative study of noise and resolution is presented with respect to the frequency and the quality factor. The study has been made using four oscillators designed to be used in quartz-crystal Microbalance sensors in damping media. The four circuits have been designed at increasing frequencies in order to improve the sensitivity or frequency change per unit of measurand. Also, the present theoretical resolution limit or best resolution achievable with a Microbalance oscillator using an AT resonator is determined, since this does not depend on frequency. However, when operating in liquid, the damping of the resonator makes the resolution diminish due to a worsening of the quality factor. The relationship between the resolution limit and the frequency and characteristics of the liquid medium is determined. The resolution worsens when the density and viscosity of the liquid is increased. However, in this case, an increase in frequency implies a small increase in resolution. Therefore, we find that when working below the maximum quality factor, for similar values, the resolution can be improved by elevating the work frequency.
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resolution in quartz crystal oscillator circuits for high sensitivity Microbalance sensors in damping media
Sensors and Actuators B-chemical, 2004Co-Authors: L Rodriguezpardo, C Gabrielli, H Perrot, J Farina, R BrendelAbstract:Abstract The use of quartz crystal oscillators as high sensitivity Microbalance sensors is limited by the frequency noise present in the circuit. To characterise the behaviour of the sensors, it is not enough to determine their experimental sensitivity, but rather it is essential to study the frequency fluctuations in order to establish the sensor resolution. This is fundamental in the case of oscillators for damping media, because the level of noise rises due to the strong decline of the quality factor of the resonator. In this paper, a comparative study of noise and resolution is presented with respect to the frequency and the quality factor. The study has been made using four oscillators designed to be used in quartz crystal Microbalance sensors in damping media. The four circuits have been designed at increasing frequencies in order to improve the sensitivity. Also, the current resolution limit of a Microbalance oscillator is determined using an AT resonator, since this does not depend on the frequency. However, when working in liquid, the damping of the resonator makes the resolution diminish due to a worsening the quality factor. The relationship between the resolution limit and the frequency and characteristics of the liquid medium has been determined. The resolution worsens when the density and viscosity of the liquid is increased. However, in this case, the increase in frequency implies a small increase in the resolution. Therefore, when working below the maximum quality factor, for similar values, the resolution can be improved by elevating the work frequency.
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immunodetection by quartz crystal Microbalance
Applied Biochemistry and Biotechnology, 2000Co-Authors: K Bizet, C Gabrielli, H PerrotAbstract:Biodetection is one of the most important challenges for the twenty-first century: many fields are concerned, mainly environmental and medical. The quartz crystal Microbalance (QCM) may offer great possibilities for this purpose: a direct response signal, which characterizes the binding event between a sensitive layer, immobilized onto the surface transducer, and the analyte to be detected, can be obtained. However, for the detection of small biomolecules such as antigens, it is quite difficult to obtain an observable signal that corresponds directly to the binding event. In general, this is owing to the lack of mass sensitivity of the commonly used QCM, with 5-to 10-MHz quartz crystals. For improving this mass sensitivity, a 27-MHz quartz resonator was developed and incorporated in a flow-through microcell. Two biospecies, IgG rabbit and peroxidase enzyme, were studied with this ultrasensitive QCM in terms of specificity, detection limit, and calibration curve.
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Validation of the mass response of a quartz crystal Microbalance coated with Prussian Blue film for ac electrogravimetry
Elsevier, 2000Co-Authors: J.j. García-jareño, C Gabrielli, H PerrotAbstract:Prussian Blue (PB) films have been considerably studied for many research applications such as electrochromic material development, new material for batteries, etc. Many analytical techniques were employed for examining PB electrochemical behaviour in solution and the quartz crystal Microbalance (QCM) used in the alternative regime (ac electrogravimetry) appeared as an attractive in situ mass sensor due to its low cost and its high mass sensitivity. Unfortunately, the validity of the common Sauerbrey equation was questionable with these films or in other terms if the QCM was used as a pure mass sensor. In this work PB film is examined through acoustic measurements and the response can be interpreted as a pure mass change if the thickness is around 0.15 μm. Over this limit, film viscoelastic contributions can affect drastically the mass change estimation: if the thickness is two times larger, the mass error reaches 40%. Keywords: Quartz crystal Microbalance, Prussian Blue, Ac electrogravimetry, Viscoelastic effect
C Gabrielli - One of the best experts on this subject based on the ideXlab platform.
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sensitivity noise and resolution in qcm sensors in liquid media
IEEE Sensors Journal, 2005Co-Authors: L Rodriguezpardo, C Gabrielli, H Perrot, J F Rodriguez, R BrendelAbstract:The use of quartz-crystal oscillators as high-sensitivity Microbalance sensors is limited by the frequency noise present in the circuit. To characterize the behavior of the sensors, it is not enough to determine their experimental sensitivity, but, rather, it is essential to study the frequency fluctuations in order to establish the sensor resolution. This is fundamental in the case of oscillators for damping media, because the level of noise rises due to the strong decline of the quality factor of the resonator. In this paper, a comparative study of noise and resolution is presented with respect to the frequency and the quality factor. The study has been made using four oscillators designed to be used in quartz-crystal Microbalance sensors in damping media. The four circuits have been designed at increasing frequencies in order to improve the sensitivity or frequency change per unit of measurand. Also, the present theoretical resolution limit or best resolution achievable with a Microbalance oscillator using an AT resonator is determined, since this does not depend on frequency. However, when operating in liquid, the damping of the resonator makes the resolution diminish due to a worsening of the quality factor. The relationship between the resolution limit and the frequency and characteristics of the liquid medium is determined. The resolution worsens when the density and viscosity of the liquid is increased. However, in this case, an increase in frequency implies a small increase in resolution. Therefore, we find that when working below the maximum quality factor, for similar values, the resolution can be improved by elevating the work frequency.
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resolution in quartz crystal oscillator circuits for high sensitivity Microbalance sensors in damping media
Sensors and Actuators B-chemical, 2004Co-Authors: L Rodriguezpardo, C Gabrielli, H Perrot, J Farina, R BrendelAbstract:Abstract The use of quartz crystal oscillators as high sensitivity Microbalance sensors is limited by the frequency noise present in the circuit. To characterise the behaviour of the sensors, it is not enough to determine their experimental sensitivity, but rather it is essential to study the frequency fluctuations in order to establish the sensor resolution. This is fundamental in the case of oscillators for damping media, because the level of noise rises due to the strong decline of the quality factor of the resonator. In this paper, a comparative study of noise and resolution is presented with respect to the frequency and the quality factor. The study has been made using four oscillators designed to be used in quartz crystal Microbalance sensors in damping media. The four circuits have been designed at increasing frequencies in order to improve the sensitivity. Also, the current resolution limit of a Microbalance oscillator is determined using an AT resonator, since this does not depend on the frequency. However, when working in liquid, the damping of the resonator makes the resolution diminish due to a worsening the quality factor. The relationship between the resolution limit and the frequency and characteristics of the liquid medium has been determined. The resolution worsens when the density and viscosity of the liquid is increased. However, in this case, the increase in frequency implies a small increase in the resolution. Therefore, when working below the maximum quality factor, for similar values, the resolution can be improved by elevating the work frequency.
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immunodetection by quartz crystal Microbalance
Applied Biochemistry and Biotechnology, 2000Co-Authors: K Bizet, C Gabrielli, H PerrotAbstract:Biodetection is one of the most important challenges for the twenty-first century: many fields are concerned, mainly environmental and medical. The quartz crystal Microbalance (QCM) may offer great possibilities for this purpose: a direct response signal, which characterizes the binding event between a sensitive layer, immobilized onto the surface transducer, and the analyte to be detected, can be obtained. However, for the detection of small biomolecules such as antigens, it is quite difficult to obtain an observable signal that corresponds directly to the binding event. In general, this is owing to the lack of mass sensitivity of the commonly used QCM, with 5-to 10-MHz quartz crystals. For improving this mass sensitivity, a 27-MHz quartz resonator was developed and incorporated in a flow-through microcell. Two biospecies, IgG rabbit and peroxidase enzyme, were studied with this ultrasensitive QCM in terms of specificity, detection limit, and calibration curve.
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Validation of the mass response of a quartz crystal Microbalance coated with Prussian Blue film for ac electrogravimetry
Elsevier, 2000Co-Authors: J.j. García-jareño, C Gabrielli, H PerrotAbstract:Prussian Blue (PB) films have been considerably studied for many research applications such as electrochromic material development, new material for batteries, etc. Many analytical techniques were employed for examining PB electrochemical behaviour in solution and the quartz crystal Microbalance (QCM) used in the alternative regime (ac electrogravimetry) appeared as an attractive in situ mass sensor due to its low cost and its high mass sensitivity. Unfortunately, the validity of the common Sauerbrey equation was questionable with these films or in other terms if the QCM was used as a pure mass sensor. In this work PB film is examined through acoustic measurements and the response can be interpreted as a pure mass change if the thickness is around 0.15 μm. Over this limit, film viscoelastic contributions can affect drastically the mass change estimation: if the thickness is two times larger, the mass error reaches 40%. Keywords: Quartz crystal Microbalance, Prussian Blue, Ac electrogravimetry, Viscoelastic effect
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quartz crystal Microbalance investigation of electrochemical calcium carbonate scaling
Journal of The Electrochemical Society, 1998Co-Authors: C Gabrielli, H Perrot, M Keddam, A Khalil, G Maurin, R Rosset, M ZidouneAbstract:Electrochemical calcareous scaling was investigated by using a quartz Microbalance in order to devise an accelerated scaling test. The chronoamperometric and the chronoelectrogravimetric curves were simultaneously recorded during scaling in carbonically pure waters. The basic processes involved in scale gravimetric evaluation were surveyed: influence of mass transport on O 2 reduction, influence of electrode vibration, and calibration of the mass measurement. Then the validation of the quartz crystal Microbalance (QCM) technique was carried out by changing some experimental conditions : flow rate, calcium concentration, and polarization potential. At the end foreign ions, commonly encountered in natural waters, were added to the synthetic waters. The scaling rate was determined by deriving the chronoelectrogravimetric curve. It was demonstrated that the QCM technique gives much more information on the scaling process than chronoamperometry and can be used as a practical scaling test.
Atsushi Takahara - One of the best experts on this subject based on the ideXlab platform.
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synthesis of a conductive polymer thin film having a choline phosphate side group and its bioadhesive properties
Chemical Communications, 2020Co-Authors: Masaru Mukai, Chaohung Cheng, Mi Chin, Chiahsin Lin, Shyhchyang Luo, Atsushi TakaharaAbstract:A conductive polymer thin film having choline phosphate as the side group was prepared. Quartz crystal Microbalance (QCM) was employed to evaluate the adsorption of the model protein, bovine serum albumin (BSA), on the films deposited on indium tin oxide (ITO) electrodes. Cell adsorption on the film was evaluated by a fibroblast NIH3T3.
M Zidoune - One of the best experts on this subject based on the ideXlab platform.
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quartz crystal Microbalance investigation of electrochemical calcium carbonate scaling
Journal of The Electrochemical Society, 1998Co-Authors: C Gabrielli, H Perrot, M Keddam, A Khalil, G Maurin, R Rosset, M ZidouneAbstract:Electrochemical calcareous scaling was investigated by using a quartz Microbalance in order to devise an accelerated scaling test. The chronoamperometric and the chronoelectrogravimetric curves were simultaneously recorded during scaling in carbonically pure waters. The basic processes involved in scale gravimetric evaluation were surveyed: influence of mass transport on O 2 reduction, influence of electrode vibration, and calibration of the mass measurement. Then the validation of the quartz crystal Microbalance (QCM) technique was carried out by changing some experimental conditions : flow rate, calcium concentration, and polarization potential. At the end foreign ions, commonly encountered in natural waters, were added to the synthetic waters. The scaling rate was determined by deriving the chronoelectrogravimetric curve. It was demonstrated that the QCM technique gives much more information on the scaling process than chronoamperometry and can be used as a practical scaling test.
Jason C Bartz - One of the best experts on this subject based on the ideXlab platform.
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investigation of bovine serum albumin bsa attachment onto self assembled monolayers sams using combinatorial quartz crystal Microbalance with dissipation qcm d and spectroscopic ellipsometry se
PLOS ONE, 2015Co-Authors: Hanh T M Phan, Shannon L Bartelthunt, Keith B Rodenhausen, Mathias Schubert, Jason C BartzAbstract:Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various self-assembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal Microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The quantity of adsorbed bovine serum albumin protein increased with increasing bovine serum albumin concentration. After equilibrium sorption was reached at pH 7.0, desorption of bovine serum albumin occurred when pH was lowered to 2.0, which is below the isoelectric point of bovine serum albumin. Our data provide further evidence that combinatorial quartz crystal Microbalance with dissipation and spectroscopic ellipsometry is a sensitive analytical tool to evaluate attachment and detachment of adsorbed proteins in systems with environmental implications.