Fe3+-Doped Aminated Lignin As Peroxidase-Mimicking Nanozymes For Rapid And Durable Colorimetric Detection Of H2o2

Nanozymes have developed rapidly as substitutes for natural enzymes. However, the toxic synthesis and the use of expensive materials seriously restrict their large-scale applications. To solve these issues, Fe3+-doped aminated lignin (Fe-AL) peroxidase-mimicking nanozymes were innovatively synthesized. The active center FeNx was introduced to alkali lignin by amination via Mannich or epoxidation methods before Fe3+-doping. The Fe-AL nanozymes could achieve accurate colorimetric detection of H2O2 in 10-100 mM and could be reused over 30 times with only a negligible decrease in catalytic activity. Besides, the color-developing systems could even maintain the blue color over 72 h, which showed great promise in designing cheap and portable H2O2 sensors. This work not only can promote the development of lignin-based nanomaterials but also provide a new way for the synthesis of nanozymes from natural macromolecules.