Magnetic Polydopamine Nanoparticles Modified with Bialdehyde Chitosan: A Novel Material Enhancing Catalytic Performance of Immobilized Lipase

In this study, we synthesized a flexible, biocompatible, and bioadhesive material for enzyme immobilization. Polydopamine (PDA) was spontaneously polymerized from dopamine and coated onto magnetic Fe₃O₄ nanoparticles. A Schiff base reaction connected PDA to double aldehyde chitosan, yielding magnetic nanoparticles (mPDA-D). The nanocomposite underwent extensive characterization via techniques such as TEM, FTIR, and XRD. Under optimized conditionsm, PDA-D efficiently immobilized lipase (89.8% efficiency). Moreover, the immobilized lipase exhibited heightened acid–base and thermal stability. Additionally, the immobilized lipase was successfully recycled eight times, achieving a high recovery rate. Compared to free lipase, immobilized enzymes exhibit superior performance during hydrolysis reaction. This innovative magnetic bio-composite, featuring robust adhesion strength and composed of natural compounds, introduces a promising strategy for enzyme immobilization.