Download Developing miniaturised electrochemical biosensors for monitoring

Title: Developing miniaturised electrochemical biosensors for
monitoring mammalian cell metabolism in vitro.
Main Supervisor: Dr Roy Pemberton
Co-Supervisors: Prof John Hart
Abstract: Electrochemical biosensors can potentially be used to monitor metabolic changes
in real time in mammalian cell cultures, and are therefore advantageous compared to
conventional end-point biochemical- and immunoassays. Recent work by this group [1, 2]
has resulted in the development of in-situ microbiosensors to detect changes in metabolite
levels in culture medium during healthy cell growth, and in response to toxic challenge.
These types of biosensor use dehydrogenase and oxidase redox enzymes, incorporated into
a novel screen-printable ink, together with requisite cofactors and redox mediators for
optimal electrochemical performance. They have included those utilising NAD as the
enzyme cofactor, in combination with the redox mediator, Meldola’s Blue (MB) [3, 4].
This PhD project will focus on developing biosensors for purine metabolism. Hypoxanthine
is the precursor of xanthine, and both are important purine metabolites of relevance in
toxicity testing, food quality monitoring and as biomarkers for disease.
Elevated
hypoxanthine levels can occur following breakdown of ATP and thus reflect changes in
intracellular energy stores. The enzyme xanthine dehydrogenase converts xanthine or
hypoxanthine to uric acid, and can use NAD as a cofactor. The hypothesis of this PhD will be
that by incorporating biosensor components into a screen-printable ink formulation, it will be
possible to develop electrochemical biosensors capable of monitoring changes in
hypoxanthine levels and to apply these to investigate toxic challenge with selected cell
types.