Scientists just built a stamp-sized sensor that can detect dopamine – the neurotransmitter tied to movement, motivation, and mood – using nothing more than a person’s tears.
The findings, which were published in the peer-reviewed journal ACS Omega, suggest that tears could offer a needle-free way to identify Parkinson’s disease and other dopamine-linked disorders before major symptoms set in.
The research team at the Federal University of Pelotas in Brazil developed the device and tested it in artificial human tears spiked with dopamine.
When they measured the sensor’s response, it accurately picked up concentrations spanning well below a healthy baseline to three times above it, a range that includes levels previously reported in the tears of people with Parkinson’s disease. In this case, the device performed reliably even in the presence of other compounds.
A postage stamp made of graphene
To build the sensor, the team used a laser to burn patterns into a thin plastic film, converting portions of it into electrically conductive graphene.
When dopamine molecules react with the graphene surface, the device produces a measurable electrical signal.
“Our sensor can detect dopamine from levels well below the healthy baseline and up to three times higher,” Lucas Minghini Gonçalves, a co-author of the study, said in a statement, adding that catching an early dopamine drop is “crucial to enabling timely, proactive therapeutic interventions.”
Current ways of tracking dopamine – like blood draws, urine tests, and implanted devices – are often slow and invasive. In comparison, tears can be collected in seconds without a needle in sight.
The sensor has only been tested in artificial tears so far – not the real thing. Getting from there to an actual diagnostic tool means clearing a fairly long runway, corresponding author Neftalí Lênin Villarreal Carreño, a professor at the Federal University of Pelotas, told Inc.
“Prior to validating our findings on real tears from Parkinson’s disease patients, we must submit our research protocol to a medical ethics committee for regulatory review,” Carreño said.
Once that clears, he said, “our roadmap involves executing a baseline study with healthy control subjects to validate the sensor’s performance in standard physiological tear matrices.” After that, the team will move on to “clinical validation using tear samples collected from patients diagnosed with Parkinson’s disease.”
The price is right
If the sensor clears regulatory and technical hurdles, the device will be accessible – and affordable.
“Currently, the estimated fabrication cost of the device at the laboratory scale averages approximately US$1 (RM4.09), and we anticipate that industrial-scale production will reduce this unit cost even further,” Carreño told Inc.
While he said the team hasn’t yet received proposals for commercialisation of licensing, he’s optimistic that such an option may be in the near future. “We are currently in the process of establishing a startup spin-off to bring our healthcare sensors to market,” he added.
And the research team isn’t stopping at dopamine.
“Our team at the Novonano Research Group is already developing adapted sensors designed to identify alternative biomarkers, such as cortisol, a hormone directly linked to stress, enabling the comprehensive monitoring of multiple hormones rather than just dopamine within bodily fluids,” Carreño said. – Inc./Tribune News Service
