Handheld sensor enables rapid detection of multiple bacteria

Rapid detection of bacteria such as E. coli or salmonella is crucial for preventing outbreaks of foodborne illnesses. Now, researchers from Osaka Metropolitan University have created a handheld device that facilitates quick onsite detection of bacteria. Led by Professor Hiroshi Shiigi from Osaka Metropolitan University, the researchers 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,” Shiigi said.

The researchers synthesised 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.

Results confirmed that the synthesised nanohybrids functioned as efficient electrochemical labels, enabling the simultaneous detection and quantification of multiple bacteria in less than an hour.

“This technique enables rapid determination of the presence or absence of harmful bacteria prior to shipment of food and pharmaceutical products, thereby helping to quickly ensure safety at the manufacturing site,” Shiigi said.

The researchers now aim to develop new organic metallic nanohybrids to detect even more bacterial species. The research findings were published in the journal Analytical Chemistry.

Top image caption: From left: Image of bacteria labelled with electrochemical markers, an electrochemical instrument to measure the data and an image of the data displayed on a smartphone. Image credit: Hiroshi Shiigi, Osaka Metropolitan University.