Handheld system detects contaminated food

The research is described in the American Institute of Physics’ Journal of Applied Physics.

According to a statement, what sets this biosensing system apart from traditional detection methods is a design that involves using a magnetoelastic biosensor — a low-cost, wireless acoustic wave sensor platform — combined with a surface-scanning coil detector.

The biosensors are coated with a bacteria-specific recognition layer containing particles of ‘phage,’ a virus that naturally recognizes bacteria, so that it’s capable of detecting specific types of pathogenic bacteria.

Traditional technologies required the sensor to be inside a coil to measure the sensor’s signals, said Yating Chai, a doctoral student in Auburn University’s materials engineering program.

‘The key to our discovery is that measurement of biosensors can now be made ‘outside the coil’ by using a specially designed microfabricated reading device,’ he said.

‘In the past, if we were trying to detect whether or not a watermelon was contaminated with salmonella on the outside of its surface, the sensors would be placed on the watermelon, and then passed through a large coil surrounding it to read the sensors,’ Chai said.

By contrast, the new biosensing system is a handheld device that can be passed over food to determine if its surface is contaminated.

‘Now, tests can be carried out in agricultural fields or processing plants in real time — enabling both the food and processing plant equipment and all surfaces to be tested for contamination,’ said Chai.