Design of a steady state pH sensor for chronic wound monitoring

  • Anna McLister

Student thesis: Doctoral Thesis


Infection is a major concern for those with chronic wounds, without appropriate and early interventions this can lead to limb threating events. At present, there is a clear requirement for the development of an in-situ sensor for point of care management of chronic wounds. The availability of such a sensor could significantly improve the clinical outcome by providing the clinician with a more detailed picture of the healing status of the wound, as well as identifying the early onset of infection.

The methodology employed here focuses on the development of a novel electrochemical sensor to monitor pH, a key biomarker used to help determine the healing status of a wound. Ultimately, it is envisioned that the proposed pH sensor could be incorporated into a conventional wound dressing to allow for periodical monitoring. A variety of carbon-based composite materials were assessed as a potential base sensing substrate. Ultimately, a carbon-based screen printed electrode was selected as the most suitable substrate due to its ability to be manufactured in bulk at a relatively low cost, which is essential considering the frequency of which wound dressings are replaced.

The novel aspects of this research are based upon a variety of surface modification techniques to improve the ability of the electrode to confer pH. The surface modification techniques that were investigated, and critically assessed, included the electroxidation of a pH sensitive redox wire onto a carbon fibre electrode and, both the electrogeneration of a pH sensitive dimer and the electropolymerisation of a custom poly flavin derivative onto carbon screen printed electrodes.The electrode performance was then assessed against a clinically relevant pH range for wound monitoring (pH 3 – 8), and the viability of the modified electrode response in a simulated wound environment using a more complex media, such as defibrinated horse blood, was investigated.
Date of AwardSept 2018
Original languageEnglish
SponsorsDEL/CAST Award with Intel & EC-Lab Ltd
SupervisorJames Davis (Supervisor) & Dewar Finlay (Supervisor)

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