'Diving board' Salmonella test developed

Testing for many strains of Salmonella at once could become faster and easier after a novel biosensor was developed by scientists at Rice University in collaboration with colleagues in Thailand and Ireland. The biosensor uses an array of what the researchers call tiny ‘diving boards’.

The researchers say the process easily outperforms tests that are currently in use in the food industry. Because it can take days to culture colonies of Salmonella, these tests can be slow.

The new process, however, delivers results within minutes from a platform that can be cleaned and re-used, the researchers say. The technology can be customised to detect any type of bacteria and to detect different strains of the same bacterium.

The diving boards are a set of microcantilevers, each of which can be decorated with different peptides that have unique binding affinities to strains of the Salmonella bacteria. When a peptide catches a bacterium, the cantilever bends ever so slightly, due to a mismatch in surface stress on the top and bottom. A fine laser trained on the mechanism catches that motion and triggers the alarm.

The system is sensitive enough to warn of the presence of a single pathogen, the researchers said.

The researchers have described the biosensor in the American Chemical Society’s journal Analytical Chemistry.