Hansani Maussawa had no plans to do a PhD. But working on a sensor to detect cocaine made her curious about how the chemistry she was exploring in the laboratory could become a practical testing device.
Now a PhD candidate at La Trobe University, Maussawa is developing biosensors to detect cocaine, methamphetamine and MDMA in saliva. She is working with Victoria Police Forensic Services to develop the technology into an affordable, portable test for potential roadside use.
The work builds on her longstanding interest in electrochemistry. “Electrochemistry has always been one of my favourite areas of chemistry because it allows you to take something happening at the molecular level and turn it into a signal that you can actually measure,” she says.
She began exploring biosensors during her master’s research. “The more I worked with biosensors, the more curious I became about how far the technology could be developed,” she says.
Towards a practical test
The cocaine sensor she developed during her master’s uses short strands of DNA, called aptamers, designed to recognise the drug. When cocaine binds to an aptamer, it changes an electrical signal that researchers can measure.
Saliva can be collected quickly and non-invasively, making it useful for roadside testing. Existing roadside tests already screen saliva for drugs, with laboratory analysis used to confirm results. Maussawa hopes biosensors could eventually offer another rapid, portable approach that complements those methods.
One particularly rewarding moment came when the cocaine sensor produced a clear response in saliva. Saliva contains salts, proteins and other substances, and its composition varies between people. That makes reliable detection harder than in a controlled laboratory solution.
“It made the research feel like it was taking an important step from a laboratory concept towards something with real-world potential,” she says.
Sharing that progress has brought encouragement beyond the laboratory. At the International Society of Electrochemistry conference in Sydney, Maussawa received a Best Poster award in her session. Presenting the work also gave her opportunities to meet researchers from around the world and hear different perspectives on its development.
Maussawa is now expanding the research to methamphetamine and MDMA and developing the components of a practical test, including disposable sensors and portable readers that could be handheld or linked to a smartphone.
Developing the technology with its users
Through MOBIUS, the ARC Research Hub for Molecular Biosensors at Point-of-Use, Maussawa established a collaboration with Victoria Police Forensic Services. They are now developing the technology together.
“This collaboration is extremely valuable because they bring the real-world forensic and roadside-testing perspective, while we bring the biosensor and electrochemistry expertise,” she says.
Police involvement helps the team understand the practical requirements of roadside testing and build them into the technology from the outset.
“MOBIUS has really helped connect our research with the people who could ultimately use the technology,” she says.
The team is working towards a prototype of the cocaine test. Further work includes checking how reliably the sensor performs in real saliva samples, improving sample collection and ensuring the complete system can withstand roadside conditions.
Businesses could contribute expertise in disposable sensor manufacturing, saliva-sampling devices, portable electronics and product development. Maussawa and her colleagues bring the sensing technology, scientific expertise and early experimental evidence.
Affordability remains central to her vision. An inexpensive, reliable test could support wider roadside screening and contribute to efforts to deter drug driving and improve road safety.
“What I enjoy most is the translational side of the research, seeing an idea begin as an experiment in the lab and then asking, ‘How can we turn this into something that someone could actually use?’"
