Blog @ NanoVic - Nanotechnology Blog

I’m sure most of you have had the rather nasty experience of food poisoning. For me, all it takes is catching a glimpse of one of my Aunt Judy’s chicken sandwiches to trigger my gag reflex. Ooohhh, the family Easter picnic 2005 will live with me forever.  Personal anecdotes aside, food-borne pathogens are an issue not only because they cause debilitating illness and death, but also because they are relatively slow to diagnose.  This is probably not so critical for the family picnic, but can save lives in the case of restaurants and establishments such as elderly residential facilities.  Current tests to detect Salmonella for example, can take up to 5 days to obtain a result and are relatively insensitive if only a low level of bacteria is present. A new nanotechnology-based biosensor has been developed to address this issue. As reported by Nanowerk, the American and Korean research team  fabricated a hetero-structured silicon/gold nanorod array by the glancing angle deposition (GLAD) thin film method and functionalized it with anti-Salmonella antibodies and organic dye molecules. The test works by amplification of the dye’s fluorescent signal when Salmonella is present.  Specifically, binding of Salmonella bacteria to gold nano-rod coupled antibodies enhances the fluorescence of the dye molecules which are immobilised on silicon.  The test is specific, sensitive and rapid, and can probably be adapted to suit detection of other food-borne pathogens as well.  Sounds good to me, Auntie Judy.