Researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) have developed a new biosensor that utilises fluorescent proteins embedded in a diatom shell to detect the presence of chemical substances.
Diatoms are tiny algae that constitute the bulk of phytoplankton, the plant base of the marine food chain. These microscopic organisms are of particular interest to materials scientists because of the intricate, highly ordered patterns that make up their mostly silica shells.
Researchers are exploring the potential of these minuscule glass cages to solve problems in a range of areas, which include sensing, catalysis and environmental remediation.
PNNL Laboratory Fellow and corresponding author Guri Roesijadi was inspired to develop the new diatom biosensor by previous work that demonstrated it was possible to insert proteins in diatom shells through genetic engineering.
Building on this research, Roesijadi and his colleagues aimed to use fluorescent proteins to turn diatoms into a biosensor. Specifically, they aimed to create a reagent-less biosensor, meaning one that detects a target substance on its own and without depending on another chemical or substance.
The well-studied marine diatom Thalassiosira pseudonana was chosen as a test case, with the PNNL team successfully inserting genes for their biosensor into the hatbox-shaped shell of the organism. The new genes allowed the diatoms to produce a protein that functions as a biosensor.
In addition, the team succeeded in making the biosensor work with the shell alone, after removal from the living diatom, providing greater flexibility for how and where the sensor can be used.
The research into this new biosensor was funded by the U.S. Office of Naval Research, which believes such technology could one day prove useful for detecting threats such as explosives in the marine environment.
Co-authors on the paper included scientists at EMSL, DOE's Environmental Molecular Sciences Laboratory at PNNL's Richland, Washington, campus.