Nature is full of fascinating creatures that produce light. From fireflies putting on mesmerizing summer displays to fish that glow eerily in the depths of the ocean, this bioluminescence is a result of chemical reactions that produce flashes of light.
In a new study published in the journal Science Advances, researchers have harnessed bioluminescent sea-dwelling algae to produce a light source that glows blue without the need for electricity or toxic chemicals. The advance could lead use in living sensors that monitor water quality, autonomous robots that work in dark environments, and eco-friendly consumer lighting such as glow sticks.
“I was curious if we could create a world in which we don’t use electricity but rather use biology to produce light,” said Wil Srubar, a civil, environmental and architectural engineering professor at the University of Colorado Boulder, in a press release. “This discovery really paves the way for engineering other living light materials and devices.”
Marine algae species such as Pyrocystis lunula produce cold blue light that is visible from the water surface. The photosynthetic organisms, which survive on sunlight and carbon dioxide, flash when they are agitated by waves, passing boats, or swimmers. The spectacular light show draws visitors to beaches in the nighttime.
But the sparking light from the glowing algae lasts for only a few milliseconds at a time. The glow is also unpredictable and is hard to control.
Acidic (top) and basic (bottom) environments trigger different bioluminescent behaviors in algae. Credit: Giulia Brachi
Researchers at UC Boulder decided to use chemistry to get the marine organisms to sustain their luminescence. In the past, researchers have suggested that exposing P. lunula to various chemical compounds could activate the algae’s luminescence reaction.
So Srubar and colleagues exposed the algae to two solutions. One was acidic, with a pH of 4, similar to that of tomato juice, while the other was a basic solution with a pH of 10, comparable to mild soap. The acidic solution was a hit. Algae in the solution stayed brightly lit for 25 minutes.
For a more practical way to use the algae, the researchers embedded the organisms into various 3D-printed objects made with naturally-derived hydrogel. In these constructs, the algae survived for weeks while glowing when exposed to the acidic solution. After four weeks, the acid-treated examples still retained 75 percent of their brightness.
Srubar and colleagues are now exploring whether P. lunula may respond to various chemicals. The goal is to harness the algae to light up when exposed to toxins and serve as a tool for water quality monitoring.
Source: Giulia Brachi et al. Chemical stimulation sustains bioluminescence of living light materials. Science Advances, 2026.
Top image: ©Anthropocene Magazine
