A team of researchers from the University of Amsterdam and the University of Warwick is taking a nature-inspired approach to improve sunscreen safety and effectiveness.
Led by Professors Wybren Jan Buma and Vasilios Stavros, the team is studying urocanic acid—a natural compound found in the skin that absorbs UV-A and UV-B rays—as a potential key ingredient in next-generation sunscreens.
Their findings, published in two papers in Physical Chemistry Chemical Physics, provide detailed insights into how urocanic acid interacts with UV light and how its properties could be optimized to create safer and more effective sunscreen filters.
Urocanic acid is naturally present in the upper layers of the skin and acts as a basic sunscreen by absorbing UV radiation.
However, its natural sun protection factor (SPF) of 1.58 is far lower than synthetic sunscreens. Another challenge is that when exposed to UV light, urocanic acid can transform into a variant that may suppress the immune system.
Despite these drawbacks, the researchers see great potential. “Urocanic acid is worth investigating,” says Professor Buma. “We believe it’s possible to design improved versions of this molecule that are both effective and safer for health and the environment.”
The team began their research with high-resolution laser spectroscopy and quantum chemical calculations, focusing on the isolated molecules of urocanic acid. This work revealed how the compound absorbs and reacts to UV light, offering a fundamental understanding of its properties.
“We are the first to study urocanic acid’s behavior at such a deep level,” says Buma. “Previous studies had experimental errors, so some data was actually from decomposition products instead of the molecule itself.”
To explore practical applications, the researchers also studied how urocanic acid behaves in solutions. Partnering with Professor Stavros and his team at the University of Warwick, they used time-resolved spectroscopy to observe the molecule’s reactions over time, from fractions of a second to hours.
The results showed that the photochemical and photophysical properties of urocanic acid can be improved by modifying the molecule and changing the solution it is in. The researchers even identified stable derivatives that may reduce the immune-suppressing effects of the natural form.
The team believes their research will inspire new interest in urocanic acid and its derivatives. These molecules could lead to innovative sunscreen filters that are safer and environmentally friendly. Additionally, their unique light-absorbing properties may open doors to other applications, such as photothermal materials.
“We’ve laid the foundation for exciting developments in sunscreen technology and beyond,” says Buma. With continued research, nature-inspired solutions like urocanic acid could redefine sun protection for the future.
