nanoparticles using metal coordinated hydrogel nanofibers. Electrospun
nanofibrous membranes filled with carbon nanotubes have been characterized by
Wan et al. (2008).
16.6.2.4 Nanogels
Nanogels are composed of cross-linked three-dimensional polymer chain networks
that are formed via covalent linkages or self-assembly processes. Two types of
nanogels can be synthetized. Support-free nanogel is the enzyme itself surrounded
with a porous polymeric network of a few nanometers in thickness. Support-based
immobilized enzyme has nanogel as a major component. Enzymes are immobilized
mainly via encapsulation and entrapment. Nanogels as enzyme support are designed
to have accessible and reactive functional groups on their surfaces that enable
covalent binding of enzyme to nanogel (Chauhan 2014).
Zhang et al. (2015) fabricated a novel biocatalyst by coating polyethylenimine
onto the native laccase followed by cross-linking with glutaraldehyde. The
immobilized enzyme exhibited significantly higher decolorization efficiency in the
degradation of a representative azo dye, Acid orange 7. Jia et al. (2013) studied
laccase nanogel that was prepared by encapsulation in polyacrylamide as the result
of N-acryloxysuccinimide modification and in situ polymerization.
16.6.2.5 Nanoflowers
Nanoflowers are innovative 3D structures for enzyme immobilization (Ge et al.
2012). Biocatalytic nanoflowers were investigated by Li et al. (2017a), who synthesized a 3D flower-like structured self-assembly hybrid nanocomposite with copper
phosphate, laccase, graphite oxide, and carbon nanotubes. The prepared
nanocomposite exhibited very high enzyme loading and improved laccase activity.
Efficient removal of organic dye and micropollutant was achieved by the hybrid
nanoflowers.
16.6.2.6 Mesoporous Nanosphere
Mesoporous nanomaterials possess high surface area, narrow pore size distribution
in the nanometer range, and defined pore geometry. Mesoporous materials are
mechanically stable. Enzymes can be immobilized by physical adsorption; however, it is a reversible process. To prevent the enzymes continuously leaching from
the material, their surface can be functionalized. Mesoporous nanoparticles have
been synthesized and tested for enzyme immobilization by Ibrahim et al. (2016)
and Kalantari et al. (2017). Specific hybrid composite can be also prepared by
combination of mesoporous nanospheres with various nanomaterials. Composite
of Fe 3 O 4 magnetic nanoparticles with mesoporous silica nanospheres was used by
354
M. Čvančarová et al.
nanofibrous membranes filled with carbon nanotubes have been characterized by
Wan et al. (2008).
16.6.2.4 Nanogels
Nanogels are composed of cross-linked three-dimensional polymer chain networks
that are formed via covalent linkages or self-assembly processes. Two types of
nanogels can be synthetized. Support-free nanogel is the enzyme itself surrounded
with a porous polymeric network of a few nanometers in thickness. Support-based
immobilized enzyme has nanogel as a major component. Enzymes are immobilized
mainly via encapsulation and entrapment. Nanogels as enzyme support are designed
to have accessible and reactive functional groups on their surfaces that enable
covalent binding of enzyme to nanogel (Chauhan 2014).
Zhang et al. (2015) fabricated a novel biocatalyst by coating polyethylenimine
onto the native laccase followed by cross-linking with glutaraldehyde. The
immobilized enzyme exhibited significantly higher decolorization efficiency in the
degradation of a representative azo dye, Acid orange 7. Jia et al. (2013) studied
laccase nanogel that was prepared by encapsulation in polyacrylamide as the result
of N-acryloxysuccinimide modification and in situ polymerization.
16.6.2.5 Nanoflowers
Nanoflowers are innovative 3D structures for enzyme immobilization (Ge et al.
2012). Biocatalytic nanoflowers were investigated by Li et al. (2017a), who synthesized a 3D flower-like structured self-assembly hybrid nanocomposite with copper
phosphate, laccase, graphite oxide, and carbon nanotubes. The prepared
nanocomposite exhibited very high enzyme loading and improved laccase activity.
Efficient removal of organic dye and micropollutant was achieved by the hybrid
nanoflowers.
16.6.2.6 Mesoporous Nanosphere
Mesoporous nanomaterials possess high surface area, narrow pore size distribution
in the nanometer range, and defined pore geometry. Mesoporous materials are
mechanically stable. Enzymes can be immobilized by physical adsorption; however, it is a reversible process. To prevent the enzymes continuously leaching from
the material, their surface can be functionalized. Mesoporous nanoparticles have
been synthesized and tested for enzyme immobilization by Ibrahim et al. (2016)
and Kalantari et al. (2017). Specific hybrid composite can be also prepared by
combination of mesoporous nanospheres with various nanomaterials. Composite
of Fe 3 O 4 magnetic nanoparticles with mesoporous silica nanospheres was used by
354
M. Čvančarová et al.