Investigation of a novel electrocatalyst for hydrogen peroxide reduction and its application to sensing and biosensing.
Gonzalez Macia, Laura (2011) Investigation of a novel electrocatalyst for hydrogen peroxide reduction and its application to sensing and biosensing. PhD thesis, Dublin City University.
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Hydrogen peroxide has, for many years, been shown to be a very important compound due to its wide and varied applications in many industrial processes as well as
biological systems. Therefore, its detection and measurement represents an important analytical issue. Traditional methods such as titrimetry or spectrophotometry have more recently been displaced by electrochemical techniques, which have proven to be an inexpensive and effective means of hydrogen peroxide determination. Hydrogen
peroxide is also the final product in many biochemical processes, most notably in oxidation reactions employing enzymes such as glucose oxidase where it is used extensively as a reporter molecule which is amenable to electrochemical detection.
In this work, a novel electrocatalyst for the reduction of hydrogen peroxide was employed as the foundation for the development of an electrochemical biosensor for glucose determination. Critical to this development was to understand the nature of the novel catalytic material which was based on a modification of silver paste electrodes,
and the fabrication of an enzyme biosensor platform capable of operating on this material. A further key theme that was explored in this work was to make the biosensor amenable to fabrication using printing techniques, including screen printing and inkjet printing.
With regard to the novel electrocatalyst, it was shown that the modification of silver screen printed electrodes (Ag SPEs) with a solution of dodecylbenzenesulphonic acid
(DBSA) and potassium chloride (KCl) significantly improved the catalytic activity of those electrodes towards the electrochemical reduction and decomposition of hydrogen peroxide. Characterisation of the modified electrodes was performed by surface analysis and electrochemical techniques. Other surfactant/salt combinations were also assessed and showed an analogous catalytic effect on the hydrogen peroxide reactions. The application of such a phenomenon for the development of novel hydrogen peroxide
sensors was evaluated.
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