3D-printed chip detects foodborne pathogens

In spite of the food industry’s efforts to fight pathogens, products can still get contaminated and people can still get sick. Much of the problem stems from the tools available to screen for harmful pathogens, which are often not effective enough at protecting the public.

Now, researchers from Guangdong University of Technology and Pudong New District People’s Hospital have developed a method for detecting foodborne pathogens that is claimed to be faster, cheaper and more effective than existing approaches. The researchers hope their technique, which has been described in the journal AIP Advances, can improve screening processes and keep contaminated food out of the hands of consumers.

Even with the best detection method, finding contaminating pathogens is not an easy task. As noted by study author Silu Feng, “Detecting these pathogens is challenging, due to their diverse nature and the various environments in which they can thrive. Additionally, low concentrations of pathogens in large food samples, the presence of similar non-pathogenic organisms and the complex nature of different food types make accurate and rapid detection difficult.”

Existing detection methods do exist, such as cell culture and DNA sequencing, but are challenging to employ at large scales. Not every batch of food can be thoroughly tested, so some contaminants inevitably slip through.

“Overall, these methods face limitations such as lengthy result times, the need for specialised equipment and trained personnel, and challenges in detecting multiple pathogens simultaneously, highlighting the need for improved detection techniques,” Feng said.

The study authors decided to take a different approach, designing a microfluidic chip that uses light to detect multiple types of pathogens simultaneously. The chip is created using 3D printing, making it easy to fabricate in large amounts and modify to target specific pathogens.

The chip is split into four sections, each of which is tailored to detect a specific pathogen. If that pathogen is present in the sample, it will bind to a detection surface and change its optical properties. This arrangement let the researchers detect several common bacteria, such as E. coli, Salmonella, Listeria and S. aureus, quickly and at very low concentrations.

“This method can quickly and effectively detect multiple different pathogens, and the detection results are easy to interpret, significantly improving detection efficiency,” Feng said. The team now plans to continue developing their device to make it even more applicable for food screening.

Image caption: The researchers created a chip with four distinct regions, meaning it is capable of testing for the presence of multiple pathogens simultaneously. Image credit: Feng et al.