Biomedical Engineering Reference
In-Depth Information
During the last few decade, great attention as an alternative synthetic
route with lower environmental impact is due to enzymatic polymeriza-
tion of aniline as compared with classical chemical oxidations because it
is carried out under milder conditions and reduces the oxidation of by-
products to water to treat extent [4-6]. h e development of the template-
assisted enzymatic polymerization approach was the great advancement
in the enzymatic polymerization of aniline [7]. h is advancement com-
prises the use of an anionic polymeric template to promote the head-to-tail
coupling of aniline radicals in order to obtain a water-soluble complex of
electrically conductive PANI. h e template-assisted polymerization of ani-
line is also performed enzymatically in a two-phase system [8], either by
chemical oxidation using both synthetic [9] and biological polymers [10]
yielding water-soluble poly-electrolyte complexes. However, in addition to
of the oxidation method employed in this approach, the separation of the
PANI from the polyanion is embedded by the high degree of complexity
between those two.
Noble metal nanostructures for example gold have gained special
interest because of the conductivity, optical properties and the biocom-
patibility [11, 12]. Gold nanoparticles were one of the most widely used
nanoparticles in the past few years, and have highly been used for immo-
bilization of enzymes for the fabrication of biosensors [13, 14]. h ese
nanoparticles act as tiny conduction centres by facilitating the transfer
of electrons; resembling the works that have shown enzymes to maintain
their enzymatic and electro-chemical activity when immobilized the on
gold nanoparticles [15.]
Enzyme immobilization has recently gained and caught much inter-
est because the quantity and quality of the desired, registered enzyme
is ot en inadequate due to high cost, enzyme instability and the limited
potential for the recovery of enzyme [16, 17]. h e magnetic nanopar-
ticles have recently attracted and invited much attention because of
their excellent and extraordinary physical and chemical properties as
compared to those of conventional bulk materials [18-22]. Ferrites are
a group of important magnetic materials that resembles many ei cient
technological applications including those in bio sensing [23, 24]. Nickel
ferrite (NiFe
2
O
4
) is known to be an interesting, voluntary ferrite, due
to its technologically important sot inverse spinel structure. Besides
this, the nickel ferrite contains improved and investigated ferromagnetic
properties that originate specii cally from magnetic moment of antipar-
allel spins between Fe
3+
ions at tetrahedral sites and Ni
2+
ions at octahe-
dral sites [25]; resulting in lower eddy of current loss, high conductivity,
