Optical Detection of Listeria in the Chilled Food Environment using Bionanosensors

<p>Successful pathogen detection is crucial for food security in the chilled food industry particularly as the threat of infectious disease is dramatically increasing due to bacterial resistance to antimicrobial drugs. Therefore, there is a strong need for faster, simple, and reliable isolation and detection of bacterial pathogens using novel point of use (POU) technology within food production environments. The use of a novel bionanosensor is proposed for the multiplexed detection of bacterial pathogens within the chilled food industry. The technology is based upon the use of surface enhanced Raman scattering (SERS) due to its high sensitivity and multiplexing capabilities. SERS active silver coated magnetic nanoparticles will be functionalised with lectins which are capable of specifically recognising and binding to carbohydrate constituents on the surface of bacteria. These lectin functionalised magnetic nanoparticles will be used to selectively capture and concentrate bacteria from swabs of production lines and mulched food samples. Silver nanoparticles will then be functionalised with a Raman reporter and a biorecognition molecule (antibodies/aptamers) which is specific towards a bacterial strain. A SERS response will only be obtained when the SERS active nanoparticle binds specifically to its bacterial target. The magnetic 'plug' will then be interrogated using small, portable Raman spectrometers that can be used in food production environments. In this way the detection strategy will be fully portable and allow for rapid, point of use detection. Once the multiplexed quantitative SERS signal is generated it needs to be analysed such that the unequivocal detection of a pathogen is made and/or the concentration of the bacteria predicted giving a response using an easily interpretable interface.</p>