Development of a molecularly imprinted polymer (MIP)-based sensor platform for the fast and low-cost detection of yeast and pathogenic bacteria

A protocol for electro-polymerisation was first developed for polymers that can specifically detect Saccharomyces cerevisiae (yeast) and subsequently expanded to polymers for the analysis of different of strains of Methicillin Resistant Staphylococcus aureus (MRSA) and Escherichia coli (E.coli). Molecularly Imprinted Polymers (MIPs) were deposited on the surface of electrodes (respectively Screen Printed Electrodes, gold and aluminium electrodes) using electrochemical methods. Parameters that were varied included the voltage, polymerization time, and monomer concentration. Cyclic Voltammetry (CV) was used to evaluate the polymerization process by monitoring the oxidation and reduction peaks of the monomers. The surface architecture of the MIPs differs with the type of electrodes that were used, which was studied with Scanning Electron Microscopy and Infrared analysis. Subsequently, to obtain high affinity binding sites on the MIP layer, extraction had to be performed. This protocol was first developed for yeast and subsequently adapted to fit with the removal of pathogenic bacteria (which requires use of Class II lab facilities). The developed MIP-SPEs were inserted into a homemade thermocouple device and exposed to various solutions of the target concentrations. For MIPs for yeast, an increase in the thermal resistance was measured after target bound to the polymer recognition layer. This is a first indication that we can use thermal detection methods, such as the Heat-Transfer Method, to determine and quantify microorganisms in buffered solutions. In the future, this will be extended to MIP-based thermal sensors for the detection of pathogenic bacteria. Advantages of these thermal sensors are their low-cost and that they allow for rapid and simple analysis, which makes them a valuable and versatile analytical tool.