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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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Temporal variations of the pH-ChemFET threshold voltage for a given polarization voltage on the integrated microelectrode (VP = 1.23 V) and different polarization times (tP = 0.2, 1, 7, 15 and 20 s).
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f6-sensors-14-03267: Temporal variations of the pH-ChemFET threshold voltage for a given polarization voltage on the integrated microelectrode (VP = 1.23 V) and different polarization times (tP = 0.2, 1, 7, 15 and 20 s).

Mentions: Then, the influence of polarization time tP was studied. Figure 6 illustrates the temporal variations of pH and associated pH-ChemFET threshold voltage for different polarization times (tP = 0.2, 1, 7, 15 and 20 s) while keeping constant the polarization voltage on the integrated microelectrode (VP = 1.23 V). In agreement with the electrochemical theory (Equation (1)), the polarization time increase is responsible for a local pH decrease and therefore a pH-ChemFET threshold voltage decrease. Nevertheless, pH variations are lower and tend to reach saturation.


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)

Temporal variations of the pH-ChemFET threshold voltage for a given polarization voltage on the integrated microelectrode (VP = 1.23 V) and different polarization times (tP = 0.2, 1, 7, 15 and 20 s).
© Copyright Policy
Related In: Results  -  Collection

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

f6-sensors-14-03267: Temporal variations of the pH-ChemFET threshold voltage for a given polarization voltage on the integrated microelectrode (VP = 1.23 V) and different polarization times (tP = 0.2, 1, 7, 15 and 20 s).
Mentions: Then, the influence of polarization time tP was studied. Figure 6 illustrates the temporal variations of pH and associated pH-ChemFET threshold voltage for different polarization times (tP = 0.2, 1, 7, 15 and 20 s) while keeping constant the polarization voltage on the integrated microelectrode (VP = 1.23 V). In agreement with the electrochemical theory (Equation (1)), the polarization time increase is responsible for a local pH decrease and therefore a pH-ChemFET threshold voltage decrease. Nevertheless, pH variations are lower and tend to reach saturation.

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