Recent technological developments have expanded and intensified the use of lanthanides in domains as diverse as renewable energy, computing, and medicine. Increasing usage of these metals raises the question of their extraction and recycling. Some bacteria and plants extract and accumulate selectively these metals. Understanding the molecular mechanisms underlying this feature is a milestone towards innovative bioremediation and bioinspired extraction strategies. Nevertheless, identifying protein-metal interactions remains challenging due to the transient character of these interactions. Here, we propose an innovative chemical biology approach for the labelling of proteins interacting with lanthanides. The PhD student will synthesize molecular probes composed of a detection module for the metal, a tag module to label the interacting protein, and an activatable linker that will enable the labelling of the protein only if interacting with a metal. They will use these chemical tools to investigate the metal interactome in bacteria or plant cells. We will thus decipher what are the key biological interactors of lanthanides, their roles in living systems and the features that enable efficient binding to metals. We expect that our findings will give insights into the toxicology of those elements and inform environmental and occupational safety policies. On the longer term, new bio-inspired strategies for their extraction, recycling, decorporation and remediation will arise from the molecular understanding of metal-life interactions, enabling a well thought-out usage of these elements to support the environmental and numerical transitions.