Simple and efficient synthesis of copper(II)-modified uniform magnetic Fe3O4@SiO2 core/shell microspheres for immobilization of cellulase

Bio and Nanomaterials Based on Fe3O4

“…Fe 3 O 4 nanoparticles have been intensively utilized to realize this objective due to its unique magnetic performance, and various practical and economical biocatalysts with improved stability and reusability have been fabricated based on Fe 3 O 4 nanoparticles, which could be easily separated from the reaction medium in the presence of external magnetic field [1,2,3,4,5,6,7,8,9,10,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114]. Proteins could be immobilized onto Fe 3 O 4 nanoparticles in the manner of physical absorption [95,96,97], covalent bonding [98,99,100,101,102,103,104], and bioconjugation [105,106,107]. Coupling reagents, such as glutaraldehyde [99,100,101,102,108,109,110], 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) [103,104,111,112,113] and sodium tripolyphosphate (TPP) [114], are often utilized to achieve much more stable immobilization via covalent bon...…”

Immobilization of cellulase on a silica gel substrate modified using a 3-APTES self-assembled monolayer

“…The decrease in activity is likely due to changes in the conformational structure of cellulase molecules and decrease in the degree of movement of the cellulase molecules (Cass and Ligler 1999 ). The typical specific activity of immobilized cellulase by covalent binding is below 52 % (Li et al 2007 , 2013 ; Wang et al 2015 ). However, the stable covalent binding also leads to very high reusability of immobilized cellulase (Wang et al 2015 ; Li et al 2013 ; Qi et al 2015 ; Zang et al 2014 ).…”

“…Researchers applied many kinds of materials as carriers for immobilization of cellulase, such as nano-silver and gold particle (Mishra and Sardar 2015 ), functionalized multiwall carbon nanotubes (Mubarak et al 2014 ), copolymers (Tata et al 2015 ), silicate clay minerals (Safari Sinegani et al 2005 ), modified Chitosan Beads (Dinçer and Telefoncu 2007 ), modified activated carbon (Anuradha Jabasingh and Valli Nachiyar 2011 ). Recently, Fe 3 O 4 magnetic nanoparticle have been paid much attention by researchers for immobilization of cellulase, due to its easy separation from the hydrolysis solution when applying magnetic field (Xu et al 2011 ; Zhang et al 2015 ; Li et al 2013 ; Qi et al 2015 ; Zang et al 2014 ). Unfortunately, the preferred pH condition for immobilized cellulase is slightly acidic (5) dissolving the Fe 3 O 4 back to Fe 2+ and Fe 3+ .…”

Immobilization of Cellulases Produced by Penicillium brevicompactum AUMC 10987, using Cross-Linkage, Chitosan-Coating and Encapsulation

“…The immobilization using iron oxide nanoparticles, enhanced the biocatalytic properties of an enzyme, including stability and reusability can provide higher surface area for high loading of enzyme (García et al 2014), this may explain the relatively higher enzyme activities than that obtained by cross-linking. Recently, ferric oxide (Fe 3 O 4) magnetic nanoparticle have been paid much attention by several researchers for immobilization of cellulases, due to its non or at least low toxicity, good biocompatibility, very good candidate, without residual magnetism, with simple, quick and lowcost collection of enzymes from a complex mixture with an external magnetic field, high enzyme loading capability, due to their large specific surface area and lower diffusion limitation in solution (Li et al 2013;Tang et al 2014).…”