<p>Micro-nano plastics (M/NPs) are pervasive environmental pollutants whose small size, persistence, and evolving surface states complicate reliable detection and remediation. As interface-dominated contaminants, their environmental behavior is largely governed by interactions at plastic–bio–nano interfaces. In this article, we review recent advances in three interconnected aspects of M/NPs research: biomolecular recognition, nano-enabled enrichment, and catalytic degradation, with particular emphasis on the central role of interfaces. Biomolecular recognition elements, including antibodies, peptides, aptamers, and molecularly imprinted materials, enable selective identification of plastics through interfacial pattern recognition. Nanomaterials such as magnetic nanoparticles, plasmonic nanostructures, metal–organic frameworks, and carbon-based materials further facilitate selective capture and signal amplification in complex matrices. Emerging degradation strategies, including engineered enzymes, enzyme–nanomaterial hybrids, nanozymes, single-atom nanozymes, and advanced oxidation processes, rely on interface-mediated adsorption, catalytic activation, and polymer transformation. Future research should therefore focus on elucidating plastic–bio–nano interfacial mechanisms and leveraging these insights to integrate molecular recognition, nano-enabled enrichment, and catalytic transformation within multifunctional platforms.</p> Graphical abstract <p></p>