Early detection of bacteria to fight the emergence of antimicrobial resistance

Prompt identification and discrimination of pathogenic microorganisms is of utmost importance to allow early adoption of effective treatment and prevent further emergence of antibiotic resistance. Current methods to identify microorganisms rely on lengthy and costly standard techniques, such as cell culture and immunoassays.
Biosensors, especially those based on an electrochemical readout, are devices that offer several advantages over conventional methods of bacteria detection, such as their fast, highly reliable, sensitive and accurate quantitative response, cost effectiveness and possibility to be miniaturised. The selectivity of a biosensor is provided by its biorecognition element, namely antibodies, DNA, enzymes, etc. To overcome limitations in the availability of bioreceptors with high affinity towards specific bacterial strains, we are developing sensing platforms that rely on the detection of secreted enzymes as indicators for the presence of bacteria. We have developed a suite of nanostructures that can be combined with enzyme-responsive materials to unlock new sensing paradigms for bacterial detection. As an example, hyaluronidase is known to be secreted by more than 90% of all Staphylococcus aureus (S. aureus) strains. Hyaluronic acid-coated nanostructured sensors have demonstrated their ability to quickly and sensitively detect critical threshold concentrations of S. aureus via the hyaluronidase-triggered degradation of the polymer coating.
The proposed project will involve the synthesis of new enzyme-responsive polymers to coat tailor-made nanostructures to be incorporated in a sensor array for multiplexed point-of-care detection of a selection of key bacteria. The candidate will gain experience in working on polymer synthesis, modification and characterisation (SEM, FTIR, XPS) of nanostructures, bacteria culture, and electrochemical sensing.