Hierarchical materials: An overview of synthesis methods and revolutionary impact on enzyme biocatalysis

Enzymes are exceptional biological catalysts given their high substrate specificity and ability to accelerate chemical reactions under mild conditions. To harness the potential of enzymes outside their native environments, immobilization technologies continue to emerge enhancing enzyme stability and handling. Insoluble materials have been widely used as enzyme supports, and their composition and structure usually determine the performance of the resulting biocatalysts. Although numerous studies have been reported on materials and techniques for enzyme immobilization, little attention has been given to hierarchical materials in enzyme stabilization and bioprocess intensification. Thus, the purpose of this review is to survey the technological potential of hierarchical materials in enzyme immobilization and bioprocessing. Herein, we describe reported synthesis methods to prepare hierarchical materials and discuss how these materials have been exploited in biocatalyst designs, their influence on the activity of enzymes post-immobilization, and the benefits they offer to large scale bioprocessing. We conclude with insights into industrially translatable hierarchical material synthesis methods and biocatalyst designs as well as aspects of research that need attention to continue advancing enzyme immobilization technologies in biocatalysis.