Development of Rare-earth-Copolymerized Polystyrene Particles for Traceable Microplastic Quantification and Imaging in Environmental and Biological Systems

We report a covalent rare-earth labeling strategy for constructing traceable polystyrene micro-and nanoplastics that supports quantitative analysis and multi-modal imaging in complex environmental and biological matrices. Polymerizable rare-earth complexes, RE(MAA)₃Phen (RE = Eu, Tb; additional lanthanides available), were synthesized using methacrylic acid and 1,10-phenanthroline ligands and subsequently incorporated into polystyrene via copolymerization, enabling stable anchoring of luminescent tracers within the polymer backbone. Using this platform, we built a size-continuous and charge-tunable particle library spanning nano-to micro-scales. Long-term incubation in representative media covering environmental, agricultural, gastrointestinal, and neural exposure scenarios shows low rare-earth leaching and robust optical signals, supporting traceable reference materials for micro-/nanoplastic quantification and imaging. This work establishes a generalizable platform for constructing traceable micro-and nanoplastic reference materials.