A La Trobe University-led team has developed an ultra-sensitive, single-use test strip that detects disease-linked microRNAs at extremely low levels. The technology could pave the way for simple, affordable point-of-need tests for conditions such as cancer.
A simple, single-use test strip developed by a research team led by La Trobe University in Australia could one day make it as easy to check for early signs of cancer as it is to monitor blood sugar.
The experimental biosensor, described in an article published in the journal Small, detects tiny molecules in blood called microRNAs, which can act as early warning signals for a range of diseases. The team’s design works much like a glucose test strip but is far more sensitive, picking up microRNAs at concentrations up to a trillion times lower than glucose.
MicroRNAs are short strands of genetic material that help regulate how genes are turned on and off. Changes in their levels have been linked to cancer and other conditions, which makes them promising biomarkers for early diagnosis and disease monitoring. But because they circulate in the body at extremely low levels, they are notoriously hard to measure outside of sophisticated labs.
“MicroRNAs provide early clues about health and diseases like cancer but they can be difficult to detect even using standard laboratory methods like PCR tests because they are often present in tiny amounts in blood, plasma, and saliva,” co-corresponding author Saimon Moraes Silva, the director of the Biomedical & Environmental Sensor Technology (BEST) Centre at La Trobe, said in a news release.
To overcome that challenge, the team built a disposable electrochemical test strip that converts the presence of a specific microRNA into an electrical signal. When a drop of blood plasma containing the target microRNA is added, the current measured by the strip changes in a way that reflects how much of that microRNA is present.
Lead author Vatsala Pithaih, a doctoral candidate in chemical sciences at La Trobe, notes that the key advance was a specialized enzyme that dramatically boosts the signal from the strip, allowing it to detect vanishingly small amounts of microRNA.
“When a sample is added to the test strip, the electrical signal decreases depending on how much microRNA of interest is present,” Pithaih said in the news release. “The enzyme amplifies this change so we can detect microRNAs at concentrations 1000 times lower.”
This signal amplification is what pushes the device into the attomolar range — an extremely low concentration — and brings the idea of a pocket-sized, lab-free microRNA test closer to reality.
Today, most microRNA testing relies on centralized laboratories, expensive instruments and trained personnel. That limits how often patients can be tested and can delay results, especially in low-resource settings or remote communities. A cheap, disposable strip that could be used at the bedside, in a clinic or even at home would open up new possibilities for screening and ongoing monitoring.
The team’s long-term goal is to integrate the strip into a simple device that non-specialists can operate, similar in spirit to consumer glucose meters or COVID-19 rapid tests.
“It is exciting to be one step closer to disease diagnosis and monitoring that is truly point-of-need: affordable, convenient, accessible, and effective,” added co-corresponding author Brian Abbey, a professor and deputy director of the La Trobe Institute for Molecular Science.
While the current work is at the experimental stage, it demonstrates that microRNAs can be detected electrically at extremely low levels using a compact, low-cost platform. Future steps will likely include testing the strips with a wider range of microRNAs, validating performance with clinical samples and developing user-friendly devices that can read and interpret the signals.
The research drew on expertise from across La Trobe, including the ARC Research Hub for Molecular Biosensors at Point-of-Use (MOBIUS), the La Trobe Institute for Molecular Science, the BEST Centre, and the Department of Biochemistry and Chemistry in the School of Agriculture, Biomedicine and Environment.
If the technology can be translated into a robust commercial product, it could help shift parts of cancer and disease diagnosis from specialized labs to everyday settings. That, researchers say, would not only make testing more accessible but could also enable earlier detection, more frequent monitoring and more personalized care for patients around the world.
Source: La Trobe University