Preparation of laccase-graphene oxide nanosheet/alginate composite: Application for the removal of cetirizine from aqueous solution

Graphene oxide (GO) nanosheet was synthesized by modified Hummer's method. Laccase was immobilized by adsorption method on GO and was followed by entrapment method in the alginate matrix. Characterizations of GO, alginate, and laccase-GO/alginate composite were studied by FT-IR, XRD, and SEM analysis. Laccase activity was increased by immobilization due to the improving the electron transfer between the laccase and substrate. Laccase-GO/alginate composite application for removal of cetirizine as a model pharmacetucal pollutant was evaluated and effect of variables including; pH of cetirizine solution, reaction temperature, and cetirizine concentration were studied. Results indicate laccase-GO/alginate composite have high storage and thermal stability and reusability with high removal efficiency of cetirizine. (C) 2016 Elsevier Ltd. All rights reserved.