Immobilization of laccase on hairy polymer grafted zeolite particles: Degradation of a model dye and product analysis with MALDI-ToF-MS

Poly(2-chloroethyl acrylate), p(CEA), as a functional polymer was grafted via surface initiated atom transfer radical polymerization (SI-ATRP) on zeolite particles. The p(CEA) grafted zeolite particles were aminated, and a ligninolytic enzyme "laccase" from Trametes versicolor was covalently immobilized on the composite particles via glutaraldehyde coupling. The amount of immobilized laccase on the zeolite-g-p(CEA) particles was determined as 17.7 mg g(-1) particles. The degradation of a model dye (i.e., Reactive Red 120; RR-120) with the free and immobilized laccases was evaluated in batch and continuous systems. The covalently immobilized laccase showed a high decolorization efficiency toward RR-120 in aqueous solution compared to the free counterpart. The resulting dye degradation products were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI ToF-MS). (C) 2014 Elsevier Inc. All rights reserved.