Reviewed by Frances BriggsNov 4 2025
A laser constructed from peanut tissue and carbon dots demonstrates that nature's imperfections can rival precision-engineered devices in performance and utility.
Study: Biomaterial-based random lasers achieved from peanut kernel doped with birch leaf–derived carbon dots. Image Credit: New Africa/Shutterstock.com
Umeå University physicists collaborated with Chinese researchers to produce a laser manufactured entirely from biomaterials, including birch leaves and peanut kernels. The environmentally friendly laser could become a low-cost and widely available tool for medical diagnosis and imaging.
The findings demonstrate how a so-called 'random laser' may be created completely of biological components.
Our study shows that it is possible to create advanced optical technology in a simple way using only local, renewable materials.
Jia Wang, Study Author and Associate Professor, Department of Physics, Umeå University
A random laser is one in which light scatters many times inside a disordered material before forming a concentrated beam. It offers enormous promise for applications such as medical imaging and early disease detection, hence it has received a lot of scientific interest. Traditional random laser materials, on the other hand, are either hazardous or costly and difficult to produce.
Jia Wang and her colleagues built the laser from two common natural materials: birch leaves and peanut seeds. They created nanometer-scale carbon dots from birch leaves to act as the gain medium, and then sliced peanut kernels into little cubes with rough and uneven surfaces that help trap and scatter light.
The laser is still driven by an external light source, but the functional components that scatter and magnify the light are entirely composed of biomaterials.
The synthesis of the carbon dots is simple and straightforward, essentially a one-step pressure-cooking process. Instead of relying on complex technology, the natural microstructure of the peanut kernel does the job on its own.
Jia Wang, Study Author and Associate Professor, Department of Physics, Umeå University
The researchers determined how much energy was necessary to make the laser produce light, and the results revealed that it works similarly to artificially engineered lasers.
In addition, the laser's emission pattern is influenced by the unique microstructure of each peanut, which could serve as a kind of spectral fingerprint. This makes it extremely difficult to repliicate, an attractive feature for security applications.
The potential of this biomaterial-based random laser extends beyond bioimaging and diagnostics. Given its low cost, renewability, and safety, it could also be developed into an optical tag for authenticating high-value documents, luxury goods, and electronic devices.
Jia Wang, Study Author and Associate Professor, Department of Physics, Umeå University
Jia Wang's research group has long been focused on using local, renewable resources to power innovative technology. Two years ago, they released a study demonstrating how birch leaves harvested on Umeå University's campus can be utilized to produce organic semiconductors. These materials are found in thin TV and mobile phone screens.
Journal Reference:
Huang, Z. et.al. (2025) Biomaterial-based random lasers achieved from peanut kernel doped with birch leaf–derived carbon dots. Nanophotonics. doi.org/10.1515/nanoph-2025-0312