▎ 摘　　要

NOVELTY - Magnetic nanocomposite comprises spherical magnetic nanoparticles bonded to surface of graphene oxide (GO), where the saccharide is covalently bound to the nanocomposite, the magnetic nanoparticle is mangansese-ferrite, and the saccharifying enzyme is cellulase selected from the group comprising cellulase, endoglucanase, exoglucanase, beta-glucosidase, cellobiose and endoxylanase. USE - Magnetic nanocomposite used for producing bioethanol (claimed). ADVANTAGE - The magnetic nanocomposite conspicuously reduces the production cost of bioethanol. DETAILED DESCRIPTION - Magnetic nanocomposite comprises spherical magnetic nanoparticles bonded to surface of graphene oxide (GO), where the saccharide is covalently bound to the nanocomposite, the magnetic nanoparticle is mangansese-ferrite, and the saccharifying enzyme is cellulase selected from the group comprising cellulase, endoglucanase, exoglucanase, beta-glucosidase, cellobiose and endoxylanase. The covalent bond is derived by the addition of one of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The magnetic nanoparticles have a particle diameter of 5-10nm, and the nanocomposite has a particle size of 200-300nm. INDEPENDENT CLAIMS are included for: (1) a method of producing magnetic nanocomposite, which involves mixing manganese (Mn) metal salt and iron (Fe) metal salt to prepare a nanocomposite, dispersing the nanocomposite in distilled water to prepare an aqueous nanocomposite solution, and mixing and agitating saccharification enzyme in an aqueous solution of the nanocomposite to immobilize a saccharifying enzyme on the surface of the nanocomposite, where the immobilization step is carried out by mixing N-(3-dimethylaminopropyl) -N-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS); and (2) a method for producing bioethanol, which involves mixing magnetic nanocomposite with biomass and an aqueous solution to ferment biomass to produce bioethanol.