Degradation of MXC by host/guest-type immobilized laccase on magnetic tubular mesoporous silica

Abstract In this paper, magnetic host/guest-type immobilized laccase was prepared by co-adsorption of super-paramagnetic particles (SPMNPs) and laccase into the pore channels of tubular mesoporous SiO 2 by the “size-matching effect”. After immobilization, the thermal stability and repetition usage-ratio of immobilized laccase were improved significantly, the loading amount of enzyme and SPMNPs was determined by Lowry’s method and EDS (Energy Dispersive Spectroscopy), respectively. Under the optimal conditions, the removal efficiency of MXC (Methoxychlor) by immobilized laccase reached 69.4% and the removal efficiency still remained 45.4% after six cycles of operations. The studies on degradation kinetics of MXC by free and immobilized laccase were also carried out, respectively. In virtue of GC–MS, 1 H NMR and 13 C NMR analysis, (CH 3 OC 6 H 5 ) 2 C CHCl and 1,1-diphenylethylene were identified as intermediate and final degradation products of MXC, respectively, further demonstrating the degradation mechanism of MXC by the immobilized laccase.