Superparamagnetic nanoparticles as versatile carriers and supporting materials for enzymes

Enzymes are highly efficient catalysts extensively employed in biotechnology. Among the many challenging aspects in this area, enzymes are yet difficult to obtain and purify, which makes them extremely expensive. Therefore, the industrial use of such expensive biocatalysts suffers from a critical point, which is the lack of efficient recovery processes. As a very promising strategy, superparamagnetic nanoparticles based on magnetite (Fe3O4) and maghemite (gamma-Fe2O3) have been recently employed as supporting materials for enzymes, exhibiting striking characteristics, such as large surface area, mobility and high mass transference. More than that, they can be easily recovered by applying an external magnetic field. In addition to their excellent environmental compatibility, the use of such superparamagnetic nanoparticles represents an effective green chemistry approach, since it prolongs, through the successive recovery cycles, the useful lifetime of the biocatalyst. Several enzymes and biomolecules, including antibodies, albumin, a-chymotrypsin, aminopeptidase, acetylcholine esterase, amylase, amyloglucosidase, celullase, epoxide hydrolases, esterase, lipase, lysozyme, pectinases, phosphatase, pyruvate phosphate dikinase, trypsin, subtilisin, urease, chitosanase, haloalkane dehalogenase, RNA polymerase, lactate dehydrogenase, alcohol dehydrogenase, galactosidase, catalase, cholesterol oxidase, D-amino acid oxidase, cathecol dioxygenase, fructosyl amino acid oxidase, L-lactate dehydrogenase, xanthine oxidase, glucose oxidase, glucosidase, laccase, peroxidases, tyrosinase and so on, have been successfully immobilized onto magnetic nanoparticles, and the recent progress in this area is focused on this review. (C) 2012 Elsevier B.V. All rights reserved.