Brazilian researchers develop sensor to detect dopamine in tears

Brazilian researchers have developed a small sensor that detects dopamine levels in human tears, a method they say could identify early signs of Parkinson’s disease before physical symptoms appear. The sensor uses electrically conductive graphene that produces a measurable signal when it interacts with dopamine.

In laboratory tests, researchers added dopamine to synthetic tears and reported that the device accurately detected concentrations similar to those found in people with Parkinson’s disease.

Development and testing Lead researcher Lucas Gonçalves and supervisor Neftalí Carreño spent five years developing the sensor at Federal University of Pelotas. The device returns results in roughly three minutes and requires only a tear sample rather than a blood draw.

Doctors currently track dopamine levels through blood tests to assess Parkinson’s risk, but those tests are described as expensive and require repeated visits. The researchers said the tear-based method could reduce cost and improve accessibility for repeated monitoring.

Future plans The team hopes to commercialize the sensor and adapt it into an at-home testing kit similar to glucose monitors used by people with diabetes. They said users could collect results at home and share the data with physicians for earlier intervention.

Parkinson’s disease is not usually listed as a direct cause of death, but it can lead to serious complications over time. Researchers said the sensor could help identify lower dopamine levels years before tremors or other symptoms develop.