Magnetic nanoparticles as versatile carriers for enzymes immobilization: A review

Enzymes are highly efficient biocatalysts and widely employed in biotechnological sectors. However, lack of (re)-purification and efficient recovery of enzymes are among the most critical and challenging aspects, which render them enormously expensive for industrial exploitability. Aiming to tackle these challenges, magnetic nanoparticles (MNPs) have gained a special place as versatile carriers and supporting matrices for immobilization purposes, owing to the exceptional properties of MNPs, such as large surface area, large surface-to-volume ratio, and mobility and high mass transference. More importantly, they can also be easily separated and recovered by applying an external magnetic field. Apart from their biocompatible micro-environment, the utilization of such MNPs represents a noteworthy green chemistry approach, since it lengthens the biocatalyst lifetime through multiple recovery cycles. According to the literature evidence, various modification and/or functionalization approaches have been developed to produce MNPs for the effective immobilization of a broad variety of industrially important enzymes and biomolecules with improved characteristics. Enzymes immobilized on MNPs displayed a wide-working pH and temperature range, as well as, improved thermal and storage stabilities than that of their pristine counterparts. Co-immobilization of multi-enzymes could also be accomplished through nanoparticle-based approaches. This review presents an updated outlook on the development and characterization of MNPs, in particular, iron-based MNPs-derived nano-constructs as support materials for enzyme immobilization.