New nano-sensor detects food poisoning organisms

Posted Jun 23, 2016 by Tim Sandle
There are several tests for food poisoning bacteria. However, most are limited by their sensitivity or the time taken to obtain a result. A new nano-sensor promises the delivery of a more accurate result.
Fast Food
A plate of food from TGI Fridays
dbasulto (CC BY-SA 2.0)
The new sensor has been devised by microbiologists and engineers at Washington State University. The new sensor is capable of amplifying the bacterial signals up to detectable levels, so that low levels of contaminating organisms can be detected.
The functional part of the sensor operates at the nano-level. The biological sensor is coated with a combination of organic and inorganic molecules designed to respond to the chemicals secreted by different bacteria.
According to Laboratory Roots magazine, the molecular array resembles the petals of a flower. For this reason the sensor has been called the “nanoflower sensor.” There is a design logic to this, for the arrangement increases the surface area of the sensor. This enables lower quantities of the released bacterial chemicals to be detected.
The device functions so that when the nano-sensor detects bacterial presence through the presence of a chemical it amplifies the signals. The low detection potentially allows contaminated food to be rejected at the point of manufacture or from stores, before it reaches the consumer.
Leading microbiologist Elisabeth Bik (@MicrobiomDigest), who works at Stamford University, tweeted: "Nanoflowers can detect bacteria before they make you sick: The particles can spot even tiny amounts of E. coli." In addtion, Tim Kilpatrick (@kilpatrick_tim), who specializes in patient health, tweeted: "Scientists are building a handheld biosensor to detect bacteria before it makes you sick."
In a research statement, the lead scientists Professor Yuehe Lin explains: “We want to take these nanoflowers and create a simple-to-use, handheld device that anyone can use anywhere.”
She added: “It’ll be as simple as using a pregnancy test strip or a glucose meter.”
The research to date has focused on the detection of Escherichia coli strain O157:H7. This bacterium is a significant and dangerous cause of illness, typically through consumption of contaminated and raw food including raw milk. Symptoms include severe, acute hemorrhagic diarrhea and abdominal cramps.
The device has yet to be built on a commercial strain and the inventors are seeking a commercial backer. Further work is underway to expand the application of the device for the screening of other food spoilage and food poisoning organisms.
The research is published in the journal Small, in a paper titled “Bioinspired Synthesis of All-in-One Organic–Inorganic Hybrid Nanoflowers Combined with a Handheld pH Meter for On-Site Detection of Food Pathogen.”