membranes can be constructed by individual graphene oxide sheets through layerby-layer stacking, resulting in excellent mechanical and optical performances
(Chen et al. 2009).
16.6.2.2 Nanotubes
Amongst various nanomaterials, carbon nanotubes possess unique structural,
mechanical, thermal, and biocompatibility properties. They have generated interest
among researchers due to their potential for biotechnological applications (Feng and
Ji 2011). The efficiency of nanotubes can be improved by surface functionalization
(Verma et al. 2013). Kinetic, thermodynamic, and stability studies of laccase
immobilized on multi-walled carbon nanotubes were performed by Tavares et al.
(2015). Immobilization of various lipases on multi-walled carbon nanotubes was
achieved by Badgujar et al. (2015). Chao et al. (2013) investigated halloysite
nanotubes and laccase immobilized through dopamine self-polymerization process.
Entrapped laccase could retain more than 90% of the initial activity after five
repeated uses and exhibited a rapid degradation rate and high degradation efficiency
with respect to the removal of phenolic compounds.
16.6.2.3 Nanofibers
Nanofibres are one-dimensional materials that offer a number of attractive features.
Among them, electrospun nanofibers seem to have high benefits. Due to their
reduced thickness and high porosity, mass transfer limitation is alleviated. They
provide high surface area and are exceptionally long and uniform in diameter.
Composites made from nanofibers are easier to recover and reuse than nanoparticles
or carbon nanotubes. They have the benefit of being easy to produce and handle.
Surface of nanofibers can be modified to optimize the enzyme loading and activity
(Wang et al. 2009).
Covalent immobilization of enzyme on the surface of electrospun polymer
nanofibers was investigated by Kim et al. (2005). This new approach of enzyme
coating on nanofibers, which yields high activity and stability, creates a useful new
biocatalytic system with potential applications in bioconversion, bioremediation,
and biosensing The collection of randomly arrayed nanofibers usually forms a
non-woven mesh or membrane (Gopal et al. 2006). Sulaiman et al. (2017) applied
cellulose nanofiber from kenaf bast fibers for enzyme immobilization and preparation of ultrafiltration membrane, which showed good enzymatic performance and
ability to be reused. Various organic and inorganic nanomaterials can be used to
make hybrid composite nanofibers with additional physical properties and mechanical stability. Laccase was efficiently immobilized on amidoxime polyacrylonitrile/
montmorillonite composite nanofibers (Feng et al. 2016) and Li et al. (2017b)
reported a convenient method for preparing co-immobilized enzyme and magnetic
16 Enzyme-Based Nanomaterials in Bioremediation
353
(Chen et al. 2009).
16.6.2.2 Nanotubes
Amongst various nanomaterials, carbon nanotubes possess unique structural,
mechanical, thermal, and biocompatibility properties. They have generated interest
among researchers due to their potential for biotechnological applications (Feng and
Ji 2011). The efficiency of nanotubes can be improved by surface functionalization
(Verma et al. 2013). Kinetic, thermodynamic, and stability studies of laccase
immobilized on multi-walled carbon nanotubes were performed by Tavares et al.
(2015). Immobilization of various lipases on multi-walled carbon nanotubes was
achieved by Badgujar et al. (2015). Chao et al. (2013) investigated halloysite
nanotubes and laccase immobilized through dopamine self-polymerization process.
Entrapped laccase could retain more than 90% of the initial activity after five
repeated uses and exhibited a rapid degradation rate and high degradation efficiency
with respect to the removal of phenolic compounds.
16.6.2.3 Nanofibers
Nanofibres are one-dimensional materials that offer a number of attractive features.
Among them, electrospun nanofibers seem to have high benefits. Due to their
reduced thickness and high porosity, mass transfer limitation is alleviated. They
provide high surface area and are exceptionally long and uniform in diameter.
Composites made from nanofibers are easier to recover and reuse than nanoparticles
or carbon nanotubes. They have the benefit of being easy to produce and handle.
Surface of nanofibers can be modified to optimize the enzyme loading and activity
(Wang et al. 2009).
Covalent immobilization of enzyme on the surface of electrospun polymer
nanofibers was investigated by Kim et al. (2005). This new approach of enzyme
coating on nanofibers, which yields high activity and stability, creates a useful new
biocatalytic system with potential applications in bioconversion, bioremediation,
and biosensing The collection of randomly arrayed nanofibers usually forms a
non-woven mesh or membrane (Gopal et al. 2006). Sulaiman et al. (2017) applied
cellulose nanofiber from kenaf bast fibers for enzyme immobilization and preparation of ultrafiltration membrane, which showed good enzymatic performance and
ability to be reused. Various organic and inorganic nanomaterials can be used to
make hybrid composite nanofibers with additional physical properties and mechanical stability. Laccase was efficiently immobilized on amidoxime polyacrylonitrile/
montmorillonite composite nanofibers (Feng et al. 2016) and Li et al. (2017b)
reported a convenient method for preparing co-immobilized enzyme and magnetic
16 Enzyme-Based Nanomaterials in Bioremediation
353