Magnetic Polydopamine Nanotubes for Enhanced Enzyme Activity and Stability

We herein report a polydopamine (PDA) based hollow nanotube magnetic material that offers preferred microenvironment for enzyme immobilization. Enzyme loading on the magnetic PDA-NTs was as high as 137.4 mg/g, with the activity retention in the order of 66%. PDA-incorporated HRP exhibited much enhanced tolerance against pH and temperature, facilitating extended storage lifetime and reusability. The enzyme also demonstrated efficient removal of dyes from industrial wastewater in an example application test. It appeared that the polydopamine based hollow nanotubes helped to maintain the three-dimensional structure of enzymes, and thus enhancing their catalytic performance.