Fabrication of the robust and recyclable tyrosinase-harboring biocatalyst using ethylenediamine functionalized superparamagnetic nanoparticles: nanocarrier characterization and immobilized enzyme properties.

Immobilized tyrosinase onto the functionalized nanoparticles with the ability to be reused easily in different reaction cycles to degrade phenolic compounds is known as a substantial challenge, which can be overcome through surface modification of the particles via proper chemical groups. Herein, the synthesis and silica coating of superparamagnetic nanoparticles using a simple procedure as well as their potential for tyrosinase immobilization were demonstrated. Therefore, N-[3-(trimethoxysilyl)propyl]ethylenediamine was used to functionalize the silica-coated nanoparticles with amine groups. Then, the ethylenediamine functionalized magnetic nanoparticles (EMNPs) were suspended in a solution containing tetrahydrofuran and cyanuric chloride (as an activating agent) to modify nanocarriers. To immobilize enzyme, a mixture of tyrosinase and cyanuric chloride functionalized magnetic nanoparticle (Cyc/EMNPs) was shaken at room temperature. The particles were characterized by EDX, TGA, SEM, FTIR, and TEM. As a result, the successful functionalization of the magnetic nanoparticles and covalent attachment of tyrosinase onto the Cyc/EMNPs were confirmed. The fabricated nano-biocatalyst particles were semi-spherical in shape. The immobilized tyrosinase (Ty-Cyc/EMNPs) exhibited remarkable reusability of six consecutive reaction cycles while no considerable loss of activity was observed for the first three cycles. Moreover, the excellent stability of the biocatalyst at different temperatures and pHs was proved. The Ty-Cyc/EMNPs with interesting features are promising for practical applications in biosensor development and wastewater treatment.