Mild PET degradation by enzymes coupled with magnetic and optical manipulation

Regarding the issue of polyethylene terephthalate (PET) waste proliferation, various methods-including physical, chemical, and biological approaches-have been proposed for PET depolymerization, with bio-enzymatic degradation emerging as a sustainable solution. However, this process is hindered by slow kinetics and enzyme thermal instability, necessitating the development of more efficient and mild strategies. This study innovatively explored enhancing the efficiency of enzyme-catalyzed PET degradation by utilizing magnetic nanoparticle modulation and the photothermal effects of photo-responsive materials. Hydrophobic Fe₃O₄ nanoparticles (NPs) formed nanochains that exhibited whirlpool motion under a rotating magnetic field, enhancing hydrolytic enzyme activity through microreaction. It revealed that at a concentration of 1 mg/mL Fe₃O₄ NPs and a magnetic field strength of 2 mT, hydrolysis efficiency increased by 38 %. Furthermore, exposure to light radiation significantly altered the physicochemical properties of plastics, including crystallinity, hydrophobicity, surface functional groups, and morphology. Photo-responsive materials exhibited a photothermal effect, increasing the temperature of the enzyme-catalyzed system and thereby enhancing degradation efficiency. Light pretreatment of MXene followed by PET hydrolase improved degradation efficiency by 148 %. The successful implementation of this innovative strategy holds promise for further advancing the practical application of bio-enzyme degradation of PET and making a substantial contribution to environmental protection efforts.