Hearing the words E. coli or salmonella and food poisoning comes to mind. Rapid detection of such bacteria is crucial in preventing outbreaks of foodborne illness. While the usual practice is to take food samples to a laboratory to see the type and quantity of bacteria that forms in a petri dish over a span of days, an Osaka Metropolitan University research team has created a handheld device for quick on-site detection.
Led by Professor Hiroshi Shiigi of the Graduate School of Engineering, the team experimented with a biosensor that can simultaneously detect multiple disease-causing bacterial species within an hour.
“The palm-sized device for detection can be linked to a smartphone app to easily check bacterial contamination levels,” Professor Shiigi explained.
His team synthesized organic metallic nanohybrids of gold and copper that do not interfere with each other, so that electrochemical signals can be distinguished on the same screen-printed electrode chip of the biosensor. These organic−inorganic hybrids are made up of conductive polymers and metal nanoparticles. The antibody for the specific target bacteria was then introduced into these nanohybrids to serve as electrochemical labels.