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Mesoporous platinum microdisc electrodes and the detection of hydrogen peroxide in analytical chemistry and scanning electrochemical microscopy

Mesoporous platinum microdisc electrodes and the detection of hydrogen peroxide in analytical chemistry and scanning electrochemical microscopy
Mesoporous platinum microdisc electrodes and the detection of hydrogen peroxide in analytical chemistry and scanning electrochemical microscopy

In this thesis, mesoporous (HI-ePt) platinum microdisc electrodes electrodeposited from the hexagonal (HI) lyotropic liquid crystalline phase are shown to be excellent amperometric sensors for the detection of hydrogen peroxide over a wide range of concentrations. Good reproducibility, high precision and accuracy of measurements are demonstrated. Mesoporous microdisc electrodes are found to retain the high rate of mass transport typical of conventional microdisc electrodes, and to have unprecedented catalytic activity due to a dramatic increase in surface area. This unique combination of properties overcomes the limitations of previous amperometric hydrogen peroxide sensors and yields outstanding qualitative and quantitative results. Calibration curves carried out using mesoporous microdiscs were of extremely high quality and showed a linear response over more than three orders of magnitude.

Application of the mesoporous microdiscs to the reduction of dissolved oxygen has also provided a significant improvement over polished microdiscs. The half wave potential for the reduction on mesoporous microdiscs is over 150 mV more positive than that on a polished microdisc of the same radius. The response is also very stable over time, retaining over 90% of the limiting current after 3000 seconds compared to under 70% over same period for a polished microdisc.

When used as probes in the scanning electrochemical microscope (SECM), mesoporous microdiscs are also known to be excellent tips for the patterning and imaging of localised enzyme activity. When operated in the generation-collection mode of the SECM, mesoporous tips were able to detect submono-layer enzyme coverages and the quantitative response of these tips enabled the determination of kinetic data for the immobilised enzymes. In addition to monitoring the activity of immobilised enzymes, the SECM was also used as a tool for the fabrication of enzyme microstructures.

University of Southampton
Evans, Stuart Anthony Grant Evans
Evans, Stuart Anthony Grant Evans

Evans, Stuart Anthony Grant Evans (2002) Mesoporous platinum microdisc electrodes and the detection of hydrogen peroxide in analytical chemistry and scanning electrochemical microscopy. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

In this thesis, mesoporous (HI-ePt) platinum microdisc electrodes electrodeposited from the hexagonal (HI) lyotropic liquid crystalline phase are shown to be excellent amperometric sensors for the detection of hydrogen peroxide over a wide range of concentrations. Good reproducibility, high precision and accuracy of measurements are demonstrated. Mesoporous microdisc electrodes are found to retain the high rate of mass transport typical of conventional microdisc electrodes, and to have unprecedented catalytic activity due to a dramatic increase in surface area. This unique combination of properties overcomes the limitations of previous amperometric hydrogen peroxide sensors and yields outstanding qualitative and quantitative results. Calibration curves carried out using mesoporous microdiscs were of extremely high quality and showed a linear response over more than three orders of magnitude.

Application of the mesoporous microdiscs to the reduction of dissolved oxygen has also provided a significant improvement over polished microdiscs. The half wave potential for the reduction on mesoporous microdiscs is over 150 mV more positive than that on a polished microdisc of the same radius. The response is also very stable over time, retaining over 90% of the limiting current after 3000 seconds compared to under 70% over same period for a polished microdisc.

When used as probes in the scanning electrochemical microscope (SECM), mesoporous microdiscs are also known to be excellent tips for the patterning and imaging of localised enzyme activity. When operated in the generation-collection mode of the SECM, mesoporous tips were able to detect submono-layer enzyme coverages and the quantitative response of these tips enabled the determination of kinetic data for the immobilised enzymes. In addition to monitoring the activity of immobilised enzymes, the SECM was also used as a tool for the fabrication of enzyme microstructures.

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Published date: 2002

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Local EPrints ID: 464857
URI: http://eprints.soton.ac.uk/id/eprint/464857
PURE UUID: 470fcaf8-64b6-4f14-83d4-cf6b28acf953

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Date deposited: 05 Jul 2022 00:05
Last modified: 05 Jul 2022 03:22

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Author: Stuart Anthony Grant Evans Evans

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