Nano-enzyme engineering: Advancing enzyme immobilization for industrial and environmental applications

Abstract

Immobilized enzyme-based catalytic systems can significantly enhance industrial processes due to their high catalytic activity and selectivity. Nano-enzymes refer to hybrid systems comprising natural biological enzymes immobilized on nanostructured supports. Enzymes immobilized on nanomaterials, termed nano-enzymes, have gained increasing attention in recent decades for their improved stability, reusability, and ease of recovery from biocatalytic reactions. Various nanostructured carriers, such as carbon nanotubes, nanoparticles with tailored morphologies, nanoporous materials, nanofibres, nanoflowers, nanogels, nanomembranes, and metal–organic frameworks (MOFs), can be engineered to host enzymes effectively. The catalytic performance of nano-enzymes is largely influenced by material characteristics, including surface-area-to-volume ratio, pore size, chemical composition, electrical conductivity, protein charge, hydrophobicity, and amino acid distribution on enzyme surfaces. Graphene-based nanocarriers are especially promising for protease immobilization, as they enhance enzyme stability against variations in pH, temperature, and environmental stress, thereby prolonging shelf life. Magnetic nanocarriers further improve immobilization efficiency, while non-magnetic systems provide biocompatibility and expand immobilization strategies. Immobilization within MOFs using biomimetic mineralization preserves enzymatic function even under harsh conditions. Optimization of these parameters creates favourable microenvironments for biocatalysts with industrial significance. Overall, nano-enzymes show strong potential in advancing catalysis, biotransformation, biosensing, and biomarker detection. Recent progress demonstrates their applicability in diverse fields, including biomedicine, biosensors, remediation of industrial pollutants, biofuel production, textiles, leather, detergents, food industries, and antifouling. This review highlights current developments in nano-enzyme design and emphasizes their role in expanding sustainable and efficient biotechnological applications.