Scientists at the University of Coimbra have developed technology that can detect electrical signals produced by microscopic marine algae, potentially opening new possibilities for monitoring aquatic environments and water quality.
The discovery could help researchers better understand how populations of marine microorganisms behave and respond to changes in their surroundings.
The technology, developed by researchers at the university’s Faculty of Sciences and Technology (FCTUC), transforms tiny electrical fluctuations into information about living microalgae populations.
Finding information in electrical noise
The research focuses on Phaeodactylum tricornutum, a species of marine microalga commonly used in scientific studies.
Researchers developed a three-dimensional electrode with a porous structure capable of detecting subtle electrical fluctuations associated with the activity of living cells.
These signals, which might ordinarily be dismissed as background electrical noise, can reveal information about biological activity.
The team found that living microalgae significantly alter the electrical fluctuations recorded by the device. As the concentration of microalgae increases, the statistical characteristics of those signals also change.
This suggests that electrical measurements could provide another way to observe changes within populations of microorganisms.
A new way to observe living organisms
Paulo Rocha, the project coordinator, explained that the research challenges the conventional understanding of electrical noise.
“We are accustomed to thinking of electrical noise as something that should be eliminated. What we show is precisely the opposite: these fluctuations can contain information about the state and dynamics of a living population. It is like gaining a new window to observe biological processes that, until now, were virtually invisible electrically,” he said.
The technology uses a specially designed electrode with very low electrical impedance, allowing it to capture signals linked to the ionic processes occurring in living cells.
According to the researchers, this configuration makes it possible to identify fluctuations that are difficult to observe using conventional techniques.
What could this mean for water quality?
Although the research remains focused on understanding the electrical behaviour of microalgae populations, its potential applications extend beyond the laboratory.
The University of Coimbra says the approach could eventually contribute to new monitoring technologies for aquatic ecology, aquaculture, water quality and bioelectrochemical systems.
In the longer term, researchers hope the technique will help scientists understand how microorganisms respond to environmental changes and how populations behave collectively.
The research was conducted by teams from the Bioelectronics & Bioenergy Research Lab, the Centre for Functional Ecology and the TERRA Associate Laboratory, all associated with the University of Coimbra’s Department of Life Sciences.
The findings suggest that electrical signals once considered unwanted interference could become a useful source of information about microscopic life in aquatic environments.