Switching between voltammetry and potentiometry in order to determine H+ or OH− ion concentration over the entire pH scale by means of tungsten disk electrode

Pašti, Igor A.; Lazarević‐Pašti, Tamara; Mentus, Slavko

doi:10.1016/j.jelechem.2011.11.019

Cited by 21 publications

(12 citation statements)

References 40 publications

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“…Figure 3d to Figure 3h shows the open circuit potential of these reference electrodes at different pH (the calibration curves). The average slope of the calibration curves was -50 ± 1 mV/pH, which was close to the values reported in other works 43,44,55 and was higher compared to commercial reference electrodes reported earlier. Both custom-made reference electrodes and the tungsten wire were stored in PBS for three more days, and the real-time response of custom-made reference electrodes at day four was evaluated against the tungsten wire under the same conditions (Figure 4a).…”

Section: Ph Response and Stability: Combination Of Tungsten Wire And supporting

confidence: 89%

PHAIR – A biosensor for pH measurement in air-liquid interface

Dabaghi

Saraei

et al. 2020

Preprint

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1AbstractIn many biological systems, pH can be used as a parameter to understand and study cell dynamics. However, measuring pH in live cell culture is limited by the sensor ion specificity, proximity to the cell surface, and scalability. Commercially available pH sensors are difficult to integrate into a small-scale cell culture system due to their size and are not cost-effective for disposable use. We made PHAIR - a new pH sensor that uses a micro-wire format to measure pH in vitro human airway cell culture. Tungsten micro-wires were used as the working electrodes, and silver micro-wires with a silver/silver chloride coating were used as a pseudo reference electrode. pH sensitivity, in a wide and narrow range, and stability of these sensors were tested in common standard buffer solutions as well as in culture media of human airway epithelial cells grown at the air-liquid interface in a 24 well cell culture plate. When measuring the pH of cells grown under basal and challenging conditions using PHAIR, cell viability and cytokine responses were not affected. Our results confirm that micro-wires-based sensors have the capacity for miniaturization, and detection of diverse ions while maintaining sensitivity. This suggests the broad application of PHAIR in various biological experimental settings.

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Section: Ph Response and Stability: Combination Of Tungsten Wire And supporting

confidence: 89%

PHAIR – A biosensor for pH measurement in air-liquid interface

Dabaghi

Saraei

et al. 2020

Preprint

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“…On the other hand, W/WO3 electrodes demonstrate a sub-Nernstian response that can be due to defects in the metal-metal oxide interface produced through oxidation of the tungsten layer. What is more, if the oxidation of the tungsten layer deposited through PVD is not optimized, native tungsten oxides such as WO2 or W2O5 (Pasti et al, 2012) can be also created on the surface along with WO3 which leads to a lower sensitivity of the final layer. In order to improve characteristics of the W/WO3 sensors, optimization of the electrooxidation procedure is in progress.…”

Section: =mentioning

confidence: 99%

Integrated electrochemical biosensor based on algal metabolism for water toxicity analysis

Tsopela

Lale

Vanhove

et al. 2014

Biosensors and Bioelectronics

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An autonomous electrochemical biosensor with three electrodes integrated on the same silicon chip dedicated to the detection of herbicides in water was fabricated by means of silicon-based microfabrication technology. Platinum (Pt), platinum black (Pt Bl), tungsten/tungsten oxide (W/WO3) and iridium oxide (Pt/IrO2) working ultramicroelectrodes were developed. Ag/AgCl and Pt electrodes were used as reference and counter-integrated electrodes respectively. Physical vapor deposition (PVD) and electrodeposition were used for thin film deposition. The ultramicroelectrodes were employed for the detection of O2, H2O2 and pH related ions H3O(+)/OH(-), species taking part in photosynthetic and metabolic activities of algae. By measuring the variations in consumption-production rates of these electroactive species by algae, the quantity of herbicides present at trace level in the solution can be estimated. Fabricated ultramicroelectrodes were electrochemically characterized and calibrated. Pt Black ultramicroelectrodes exhibited the greatest sensitivity regarding O2 and H2O2 detection while Pt/IrO2 ultramicroelectrodes were more sensitive for pH measurement compared to W/WO3 ultramicroelectrodes for pH measurement. Bioassays were then conducted to detect traces of Diuron herbicide in water samples by evaluating disturbances in photosynthetic and metabolic activities of algae caused by this herbicide.

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“…Concerning tungsten oxide based microelectrodes, they exhibited linear, sub-Nernstian sensitivity (around 55 mV/pH). Such value is representative of stoichiometric tungsten oxide WO3 rather than non-stoichiometric oxide [38,41,42].…”

Section: Deposition Of Tungsten Thin Filmsmentioning

confidence: 99%

“…Secondly, tungsten oxide thin films were studied for the mass fabrication of photo-electrochemical devices while developing integration processes based on physical vapour deposition [32][33][34][35]. Thirdly, it was successfully elaborated as a sensitive material for the fabrication of pH-ChemFET microdevices [36] as well as pH-sensitive microelectrodes [37][38][39][40][41]. In most cases, tungsten oxidation was obtained by electro-oxidation in basic solutions, leading to the formation of stable WO3 thin films.…”

Section: Introductionmentioning

confidence: 99%

Integration of tungsten layers for the mass fabrication of WO3-based pH-sensitive potentiometric microsensors

Lale

Tsopela

Civélas

et al. 2015

Sensors and Actuators B: Chemical

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(W/WO3-Ag/AgCl) and (Pt/IrO2-Ag/AgCl) potentiometric microdevices were developed for pH measurement in liquid phase using a (Pt-Pt-Ag/AgCl) electrochemical microcells (ElecCell) silicon-based technological platform. A special emphasis was placed on the mass fabrication of the W/WO3 microelectrode using sputtering deposition and oxygen plasma processes. Compared to the Pt/IrO2-based one, the W/WO3-based microelectrodes showed lower performances regarding the pH measurement. Nevertheless, since W/WO3 microelectrodes yielded quasi-Nernstian sensitivity (around 55 mV/pH) in the [2-12] pH range, tungsten oxide WO3 can be considered as a good candidate for the mass fabrication of pH microsensors using silicon technologies, even if important temporal drift (at least 6 millivolts per hour) and high hysteresis (around 50 mV) were also evidenced.

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Switching between voltammetry and potentiometry in order to determine H+ or OH− ion concentration over the entire pH scale by means of tungsten disk electrode

Cited by 21 publications

References 40 publications

PHAIR – A biosensor for pH measurement in air-liquid interface

PHAIR – A biosensor for pH measurement in air-liquid interface

Integrated electrochemical biosensor based on algal metabolism for water toxicity analysis

Integration of tungsten layers for the mass fabrication of WO3-based pH-sensitive potentiometric microsensors

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