QUT researchers have developed a biosensor that detects rare earth elements using a hybrid protein that acts as a molecular switch. Credit: QUT
QUT researchers created a biosensor using engineered proteins to detect and extract rare earth elements, offering a potential solution to growing demand and environmental challenges.
QUT synthetic biologists have developed a prototype for an innovative biosensor capable of detecting rare earth elements, with the potential for modification to suit various other applications.
Lanthanides (Lns) are essential elements used in electronics, electric motors, and batteries. However, current extraction methods are costly, environmentally damaging, and unable to meet the growing demand.
Professor Kirill Alexandrov and his colleagues from the QUT Centre of Agriculture and Bioeconomy and the ARC Centre of Excellence in Synthetic Biology engineered proteins to create molecular nanomachines that generate easily detectable signals when they selectively bind to Lns.
Along with Professor Alexandrov, the international research team involved QUT researchers Dr. Zhong Guo, Patricia Walden, and Dr. Zhenling Cui, in collaboration with researchers from CSIRO Advanced Engineering Biology Future Science Platform and Clarkson University (USA).
Breakthrough: A Hybrid Protein “Switch”
Publishing their findings in Angewandte Chemie International, the team describes engineering a hybrid protein, or “chimera,” by combining a lanthanide-binding protein, LanM, with an antibiotic-degrading enzyme called beta-lactamase.
This hybrid acts like a “switch” that becomes active only when lanthanides are present. It can be used to detect and quantify Lns in liquids, producing a visible color change or an electrical signal.
Impressively, bacteria modified with these chimeras were able to survive in the presence of antibiotics that otherwise would kill them —but only when lanthanides were present. This highlights how precisely the proteins respond to these rare metals.
“This work opens up exciting possibilities for using biology to detect and recover rare earth metals,” Professor Alexandrov said.
“The prototype can also be modified for various biotechnological applications, including construction of living organisms capable of detecting and extracting valuable metals.”
Future Developments and Industry Applications
The research team now plans to work on increasing the specificity of the molecular switch to better differentiate between closely related rare earth elements. It also explores the possibility of developing switches for other critical elements. The team is in active discussions with potential industry partners who are interested in this technology.
“We also want to explore using the tool to engineer microbes that can directly extract rare earth minerals from ocean water,” Professor Alexandrov said.
“This is probably one of the best-performing switches made and has given us a lot of insight into the mechanics of protein switches.”
Reference: “Lanthanide-Controlled Protein Switches: Development and In Vitro and In Vivo Applications” by Zhong Guo, Oleh Smutok, Chantal Ronacher, Raquel Aguiar Rocha, Patricia Walden, Sergey Mureev, Zhenling Cui, Evgeny Katz, Colin Scott and Kirill Alexandrov, 24 January 2025, Angewandte Chemie International Edition.
