title: Magnetic mesoporous silica nanoparticles: fabrication and their laccase immobilization performance.
abstract: Newly large-pore magnetic mesoporous silica nanoparticles (MMSNPs) with wormhole framework structures were synthesized for the first time by using tetraethyl orthosilicate as the silica source and amine-terminated Jeffamine surfactants as template. Iminodiacerate was attached on these MMSNPs through a silane-coupling agent and chelated with Cu(2+). The Cu(2+)-chelated MMSNPs (MMSNPs-CPTS-IDA-Cu(2+)) showed higher adsorption capacity of 98.1 mg g(-1)-particles and activity recovery of 92.5% for laccase via metal affinity adsorption in comparison with MMSNPs via physical adsorption. The Michaelis constant (K(m)) and catalytic constant (k(cat)) of laccase immobilized on the MMSNPs-CPTS-IDA-Cu(2+) were 3.28 mM and 155.4 min(-1), respectively. Storage stability and temperature endurance of the immobilized laccase on MMSNPs-CPTS-IDA-Cu(2+) increased significantly, and the immobilized laccase retained 86.6% of its initial activity after 10 successive batch reactions operated with magnetic separation.
authors.affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Chen
authors.initials: C
authors.lastname: Guo
authors.forename: Liang-rong
authors.initials: LR
authors.lastname: Yang
authors.forename: Chun-Zhao
authors.initials: CZ
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D042845:Laccase / Q000378:metabolism*; D008280:Magnetics / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D055454:Trametes / Q000201:enzymology*
chemical_list: D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D042845:Laccase