Uni of Newcastle team invents a tiny lickable strip to detect disease

Semi-conducting polymers look set to revolutionise many long-entrenched medical systems, from blood sugar monitoring for diabetic patients to testing for a range of diseases including Covid, and potentially even for detecting conditions such as post-traumatic stress disorder. Paul Dastoor, physics professor and director of Newcastle University’s Centre for Organic Electronics, has spent his career researching these revolutionary polymers and developing devices that make the most of their potential.

The flexible polymers can used as an electronic ink with semi-conducting behaviour and printed on to plastic strips, he says. A smear of saliva, from licking the strip, will interact with the ink to produce a reading.

“We can embed a bio-molecule, for instance the enzyme to detect glucose, into the ink and we can detect glucose incredibly sensitively,” Dastoor says, adding the strip can then be connected to a reader to see the data, and the strips can also be made with wireless functionality for data transmission.

The printable saliva-based glucose biosensor is 100 times more sensitive than traditional blood sensors, and potentially less expensive and less painful – an important consideration when children have diabetes.

The semi-conducting polymers have enormous potential across a range of medical uses, Dastoor adds. “We can print electronic devices, like solar cells; we can print transistors with biological molecules embedded in them.”

Big pharma has already demonstrated keen interest in the potential of these semi-conducting polymer devices and conversations with large international companies interested in providing healthcare to low- and middle-income countries are underway, Dastoor says.

Some of those nations are starting to see the adverse impacts of dietary changes, such as the increased consumption of highly processed foods, he adds, but they lack the resources and facilities to manage chronic diseases such as diabetes. Left unmanaged, diabetes can lead to glaucoma and eventually blindness as well as compromised blood circulation, and finally even to amputations of toes and feet.

The revolutionary blood sugar biosensors could be on the market within two years, Dastoor says. “We’re ready to build first factories and print the first devices.” The potential for this semi-conducting polymer technology platform is enormous, he adds.

Bio-molecules of different kinds can be embedded in semi-conducting polymer to create biosensors which can signal a range of different diseases or conditions detected in the saliva sample. One type of biosensor could signal the presence of the Covid spike protein, others might detect a wide range of other diseases including dengue. Another type could detect pregnancy. Others could detect cholesterol and cortisol levels.

“There are an enormous number of accessible biomarkers in the saliva,” Dastoor adds. “We haven’t developed devices for all those applications, but there’s the exciting prospect of being able to do so.”

Improving nerve connectivity could be next on the agenda for this scientific breakthrough. “We’ve published preliminary papers on being able to interface these semi-conducting polymers directly with cells, such as nerve cells,” Dastoor says. “We’re starting to show how we can communicate with nerve cells electronically through these materials.”

The Australian