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Modelling of impulsional pH variations using ChemFET-based microdevices: application to hydrogen peroxide detection.

Diallo AK, Djeghlaf L, Launay J, Temple-Boyer P - Sensors (Basel) (2014)

Bottom Line: This ElecFET device consists of a pH-Chemical FET (pH-ChemFET) with an integrated microelectrode around the dielectric gate area in order to trigger electrochemical reactions.Combining oxidation/reduction reactions on the microelectrode, water self-ionization and diffusion properties of associated chemical species, the model shows that the sensor response depends on the main influential parameters such as: (i) polarization parameters on the microelectrode, i.e., voltage (Vp) and time (t(p)); (ii) distance between the gate sensitive area and the microelectrode (d); and (iii) hydrogen peroxide concentration ([H2O2]).The model developed can predict the ElecFET response behaviour and creates new opportunities for H2O2-based enzymatic detection of biomolecules.

View Article: PubMed Central - PubMed

Affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France. dialloabdoukarim@yahoo.fr.

ABSTRACT
This work presents the modelling of impulsional pH variations in microvolume related to water-based electrolysis and hydrogen peroxide electrochemical oxidation using an Electrochemical Field Effect Transistor (ElecFET) microdevice. This ElecFET device consists of a pH-Chemical FET (pH-ChemFET) with an integrated microelectrode around the dielectric gate area in order to trigger electrochemical reactions. Combining oxidation/reduction reactions on the microelectrode, water self-ionization and diffusion properties of associated chemical species, the model shows that the sensor response depends on the main influential parameters such as: (i) polarization parameters on the microelectrode, i.e., voltage (Vp) and time (t(p)); (ii) distance between the gate sensitive area and the microelectrode (d); and (iii) hydrogen peroxide concentration ([H2O2]). The model developed can predict the ElecFET response behaviour and creates new opportunities for H2O2-based enzymatic detection of biomolecules.

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H2O2 analytical responses of the ElecFET microdevice (VP = 0.32, 0.35, 0.38, 0.42, 0.45 V and tP = 30 s) for two different distances between the integrated microelectrode and the pH-sensitive gate: (a) d = 30 μm and (b) d = 210 μm.
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f10-sensors-14-03267: H2O2 analytical responses of the ElecFET microdevice (VP = 0.32, 0.35, 0.38, 0.42, 0.45 V and tP = 30 s) for two different distances between the integrated microelectrode and the pH-sensitive gate: (a) d = 30 μm and (b) d = 210 μm.

Mentions: In order to quantify the pH variation, its minimal value and more precisely the associated minimal threshold voltage value have been studied according to [H2O2] concentration for two integration levels, i.e., for two distances (d = 30 and 210 μm) between the integrated microelectrode and the pH-ChemFET gate sensitive area (Figure 10 respectively). Simulation results exhibit linear variations for several concentration decades (sensitivity ≈ 60 mV/decade). Such Nernstian sensitivity is related to linear variations of the [H3O+] concentration with the [H2O2] concentration at the microelectrode surface (cf.Equation (3)). This result demonstrates that the pH-ElecFET microdevice can be effectively used for the potentiometric detection of hydrogen peroxide. Furthermore, by increasing the polarization voltage VP and/or the integration level, H2O2 detection range and detection limit can be improved.


Modelling of impulsional pH variations using ChemFET-based microdevices: application to hydrogen peroxide detection.

Diallo AK, Djeghlaf L, Launay J, Temple-Boyer P - Sensors (Basel) (2014)

H2O2 analytical responses of the ElecFET microdevice (VP = 0.32, 0.35, 0.38, 0.42, 0.45 V and tP = 30 s) for two different distances between the integrated microelectrode and the pH-sensitive gate: (a) d = 30 μm and (b) d = 210 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3958244&req=5

f10-sensors-14-03267: H2O2 analytical responses of the ElecFET microdevice (VP = 0.32, 0.35, 0.38, 0.42, 0.45 V and tP = 30 s) for two different distances between the integrated microelectrode and the pH-sensitive gate: (a) d = 30 μm and (b) d = 210 μm.
Mentions: In order to quantify the pH variation, its minimal value and more precisely the associated minimal threshold voltage value have been studied according to [H2O2] concentration for two integration levels, i.e., for two distances (d = 30 and 210 μm) between the integrated microelectrode and the pH-ChemFET gate sensitive area (Figure 10 respectively). Simulation results exhibit linear variations for several concentration decades (sensitivity ≈ 60 mV/decade). Such Nernstian sensitivity is related to linear variations of the [H3O+] concentration with the [H2O2] concentration at the microelectrode surface (cf.Equation (3)). This result demonstrates that the pH-ElecFET microdevice can be effectively used for the potentiometric detection of hydrogen peroxide. Furthermore, by increasing the polarization voltage VP and/or the integration level, H2O2 detection range and detection limit can be improved.

Bottom Line: This ElecFET device consists of a pH-Chemical FET (pH-ChemFET) with an integrated microelectrode around the dielectric gate area in order to trigger electrochemical reactions.Combining oxidation/reduction reactions on the microelectrode, water self-ionization and diffusion properties of associated chemical species, the model shows that the sensor response depends on the main influential parameters such as: (i) polarization parameters on the microelectrode, i.e., voltage (Vp) and time (t(p)); (ii) distance between the gate sensitive area and the microelectrode (d); and (iii) hydrogen peroxide concentration ([H2O2]).The model developed can predict the ElecFET response behaviour and creates new opportunities for H2O2-based enzymatic detection of biomolecules.

View Article: PubMed Central - PubMed

Affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France. dialloabdoukarim@yahoo.fr.

ABSTRACT
This work presents the modelling of impulsional pH variations in microvolume related to water-based electrolysis and hydrogen peroxide electrochemical oxidation using an Electrochemical Field Effect Transistor (ElecFET) microdevice. This ElecFET device consists of a pH-Chemical FET (pH-ChemFET) with an integrated microelectrode around the dielectric gate area in order to trigger electrochemical reactions. Combining oxidation/reduction reactions on the microelectrode, water self-ionization and diffusion properties of associated chemical species, the model shows that the sensor response depends on the main influential parameters such as: (i) polarization parameters on the microelectrode, i.e., voltage (Vp) and time (t(p)); (ii) distance between the gate sensitive area and the microelectrode (d); and (iii) hydrogen peroxide concentration ([H2O2]). The model developed can predict the ElecFET response behaviour and creates new opportunities for H2O2-based enzymatic detection of biomolecules.

Show MeSH