Flexible Recyclable Cellulose Paper Templated Cu-Doped Polydopamine Membranes with Dual Enzyme-Like Activity

The development of high-efficiency enzyme mimics is of great significance in the field of biocatalysis. However, it remains challenging to design novel enzyme mimics with multiple enzyme-like activities, excellent stability, and good reusability. Herein, a facile molecular assembly strategy to construct dialdehyde cellulose (DAC) templated Cu-doped polydopamine (DAC@PDA/Cu) membrane with dual enzyme-like activities is presented. The Schiff base bonds formed between polydopamine (PDA) and DAC can not only accelerate the adhesion of PDA thin layer but also contribute to Cu-loading and high stability of DAC@PDA/Cu membrane. Importantly, the assembled DAC@PDA/Cu membrane exhibits a remarkable catalytic activity that is superior to the natural laccase along with high stability and excellent reusability. Moreover, the DAC@PDA/Cu membrane also demonstrates peroxidase-like activity, and it is successfully applied in the sensitive detection of ascorbic acid (AA). This work will provide a new paradigm methodology for rational design and practical applications of enzyme mimics based on bioinspired molecular assemblies.