Light-driven biomimetic cleavage of natural polysaccharides by a Fe3O4@HKUST-1 nanozyme mimicking LPMO

The controlled depolymerization of natural polysaccharides remains a challenging task. In this work, a core-shell nanozyme, Fe 3 O 4 @HKUST-1, was developed to functionally mimic the catalytic behavior of lytic polysaccharide monooxygenases (LPMO) while providing photo-responsiveness and magnetic recoverability. The Fe 3 O 4 core serves as a magnetic and photoactive component, enabling both efficient charge transfer and facile catalyst recycling, whereas the HKUST-1 shell offers redox-active Cu(II)/Cu(I) centers that generate reactive oxygen species under light irradiation. Using 4-nitrophenyl β-D-glucopyranoside as a model substrate, the catalyst efficiently promoted glycosidic bond cleavage, with singlet oxygen ( 1 O 2 ) identified as the predominant oxidant. More importantly, Fe 3 O 4 @HKUST-1 enabled the light-assisted oxidative hydrolysis of peach gum, yielding water-soluble low-molecular-weight oligosaccharides. This study introduces a robust MOF-based nanozyme approach for LPMO-like functional catalysis, offering a promising pathway for valorizing natural polysaccharides into functional food ingredients. • Constructed a Fe 3 O 4 @HKUST-1 nanozyme mimicking LPMO for light-driven depolymerization. • Identified singlet oxygen as the dominant species enabling selective bond cleavage. • Enabled photocatalytic hydrolysis of peach gum to yield soluble oligosaccharides.