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J. A. Elegbede and A. Lateef
nanocomposites (Co-MGNCs) were synthesized in a simplistic one-pot electrochemical process. Characterization of the Co-MGNCs via X-ray photoelectron spectroscopy and field emission scanning electron microscopy techniques revealed that
cobalt element was greatly dispersed in the graphene scaffold. It was reported that
the nanocomposite could effectively catalyze the reaction between H 2 O 2 and 3,3,5,5tetramethylbenzidine (TMB). A simple, visual and sensitive colorimetric method
based on Co-MGNCs nanocomposite as peroxidase mimetic was proven for detecting
dopamine which was productively applied to dopamine detection in samples of
human serum. Zheng et al. (2013) depicted that graphene dots (GDs) possessed very
proficient peroxidase-like catalytic potentials which was much superior than activity
of graphene oxide (GO) having larger sizes. GDs were synthesized when Vulcan
XC-72 carbon black was dispersed in 7 M nitric acid, then sonicated for 1 h, and
refluxed for 24 h at 130 °C; eventually, a reddish-brown solid was obtained. The GDs
synthesized was reported to mediate the oxidation of 3,3,5,5-tetramethylbenzidine
(TMB) (peroxidase substrate) with H 2 O 2 in attendance to generate a blue product,
which can be employed for H 2 O 2 detection by examining the absorbance change.
This catalytic reaction was said to be capable of being used for detection of some
other analytes (such as reduced glutathione (GSH) and glucose) by examining the
generation or consumption of H 2 O 2 . This GDs-based system permitted detection of
as little as 10 nM of H 2 O 2 , which is a lot lesser than that of other nanomaterialcatalyzed schemes. However, the limit of detection of this system was 0.5 μM
for glucose and GSH detection. Also, hemin/reduced graphene oxide (hemin/rGO)
nanocomposite created by a easy and facile hydrothermal method not including
addition of any reducing agent was reported by Liu et al. (2016). The synthesized
hemin/rGO nanocomposite displayed peroxidase-like activity by catalyzing the reaction of indole-3-acetic acid (IAA) in the presence of oxygen. The oxygen consumption has a linear correlation with IAA concentration in the range from 0.1 to 43 μM
and from 43 to 183 μM with the limit of detection as small as 0.074 μM.
Moreover, a simplistic technique to synthesize processable AgNPs, bimetallic
nanoparticles (Ag–Au/Au–Ag) and a decorated Prussian blue nanocomposite (PB–
AgNP) was reported by Pandey et al. (2015). The synthesis was facilitated by 3aminopropyltrimethoxysilane (APTMS) and cyclohexanone as reducing agents. The
peroxidase mimectic potentials of the nanomaterials were spectrophotometrically
determined by quantifying the development of the oxidized product of odianisidine
at 430 nm. The nanocomposite displayed produced better catalytic activity than that
recorded with natural enzyme and the peroxidase mimetic capacity was observed
to correspond to the concentration of 3-APTMS which revealed the prospective
potential of functional AgNPs in bioanalytical purposes. According to Kim et al.
(2016), AuNPs were deposited on carboxylated nanodiamonds (NDs) by in situ
chemical reduction of Au
+ ions to fabricate a novel nanodiamond–gold nanocomposites (NDAus), which displayed potentials to mediate o-phenylenediamine oxidation
carried out in hydrogen peroxide presence comparable to peroxidase. The remarkable
catalytic activity was displayed only by the AuNPs-decorated nanodiamonds and not
observed in either AuNPs or nanodiamond individually. The studies on the kinetics
of the oxidative catalysis of the process showed that NDAus produced a ping-pong
J. A. Elegbede and A. Lateef
nanocomposites (Co-MGNCs) were synthesized in a simplistic one-pot electrochemical process. Characterization of the Co-MGNCs via X-ray photoelectron spectroscopy and field emission scanning electron microscopy techniques revealed that
cobalt element was greatly dispersed in the graphene scaffold. It was reported that
the nanocomposite could effectively catalyze the reaction between H 2 O 2 and 3,3,5,5tetramethylbenzidine (TMB). A simple, visual and sensitive colorimetric method
based on Co-MGNCs nanocomposite as peroxidase mimetic was proven for detecting
dopamine which was productively applied to dopamine detection in samples of
human serum. Zheng et al. (2013) depicted that graphene dots (GDs) possessed very
proficient peroxidase-like catalytic potentials which was much superior than activity
of graphene oxide (GO) having larger sizes. GDs were synthesized when Vulcan
XC-72 carbon black was dispersed in 7 M nitric acid, then sonicated for 1 h, and
refluxed for 24 h at 130 °C; eventually, a reddish-brown solid was obtained. The GDs
synthesized was reported to mediate the oxidation of 3,3,5,5-tetramethylbenzidine
(TMB) (peroxidase substrate) with H 2 O 2 in attendance to generate a blue product,
which can be employed for H 2 O 2 detection by examining the absorbance change.
This catalytic reaction was said to be capable of being used for detection of some
other analytes (such as reduced glutathione (GSH) and glucose) by examining the
generation or consumption of H 2 O 2 . This GDs-based system permitted detection of
as little as 10 nM of H 2 O 2 , which is a lot lesser than that of other nanomaterialcatalyzed schemes. However, the limit of detection of this system was 0.5 μM
for glucose and GSH detection. Also, hemin/reduced graphene oxide (hemin/rGO)
nanocomposite created by a easy and facile hydrothermal method not including
addition of any reducing agent was reported by Liu et al. (2016). The synthesized
hemin/rGO nanocomposite displayed peroxidase-like activity by catalyzing the reaction of indole-3-acetic acid (IAA) in the presence of oxygen. The oxygen consumption has a linear correlation with IAA concentration in the range from 0.1 to 43 μM
and from 43 to 183 μM with the limit of detection as small as 0.074 μM.
Moreover, a simplistic technique to synthesize processable AgNPs, bimetallic
nanoparticles (Ag–Au/Au–Ag) and a decorated Prussian blue nanocomposite (PB–
AgNP) was reported by Pandey et al. (2015). The synthesis was facilitated by 3aminopropyltrimethoxysilane (APTMS) and cyclohexanone as reducing agents. The
peroxidase mimectic potentials of the nanomaterials were spectrophotometrically
determined by quantifying the development of the oxidized product of odianisidine
at 430 nm. The nanocomposite displayed produced better catalytic activity than that
recorded with natural enzyme and the peroxidase mimetic capacity was observed
to correspond to the concentration of 3-APTMS which revealed the prospective
potential of functional AgNPs in bioanalytical purposes. According to Kim et al.
(2016), AuNPs were deposited on carboxylated nanodiamonds (NDs) by in situ
chemical reduction of Au
+ ions to fabricate a novel nanodiamond–gold nanocomposites (NDAus), which displayed potentials to mediate o-phenylenediamine oxidation
carried out in hydrogen peroxide presence comparable to peroxidase. The remarkable
catalytic activity was displayed only by the AuNPs-decorated nanodiamonds and not
observed in either AuNPs or nanodiamond individually. The studies on the kinetics
of the oxidative catalysis of the process showed that NDAus produced a ping-pong