214
J. A. Elegbede and A. Lateef
assessed in laccase substrates oxidation (Wang et al. 2017b). This synthesized platinum nanozyme demonstrated good stability in the temperature range of 20–90 °C
and pH 3–9, beyond the range for normal laccase. The most proficient was the C 10 -
templated Pt nanozyme (4.6 nm sized) which displayed three times superior affinity
with regard to 2,4-dichlorophenol than natural laccase. DNA-stabilized Pt nanoparticles produced excellent catalytic potentials in substrates oxidation which include
catechol, dopamine, p-phenylenediamine and hydroquinone. In addition, Xu et al.
(2014) described the fabrication of nanoceria with oxidase-like activity wherein a
solution containing a mixture of 1 M cerium (III) nitrate solution and 1.0 M dextran
were added in a dropwise manner to 30.0 ml ammonium hydroxide solution (25%)
which was stirred continuously for 24 h at ambient temperature, then centrifuged and
precipitated. Nucleoside triphosphates (NTPs) were applied to augment the oxidaselike potential of nanoceria, and it was observed that the improvement directly corresponded with the specific type of NTP applied. The enhancement effect was said to be
in consequence of coupling of the oxidative reaction of nanoceria with the hydrolysis
reactions of NTP. And founded on the effectiveness of the NTP-improved oxidaselike potential of nanoceria, series effective colorimetric assays for single-nucleotide
polymorphism (SNP) typing were generated.
The detoxification processes in the mitochondria involve sulfite oxidase, where
defects in the enzyme lead to harsh infant disease resulting in early death with
no capable or cost-effective therapy in view. Ragg et al. (2014) reported that
molybdenum trioxide (MoO 3 ) nanoparticles demonstrated a fundamental biomimetic
sulfite oxidase (SuOx) activity. The molybdenum trioxide nanoparticles was synthesized by dissolving 10.4 mmol of molybdenum powder and H 2 O 2 in distilled
water and cooled to 0 °C. Acetic acid was added dropwise under rigorous stirring eventually leading to creation of a yellow precipitate washed with distilled
water and ethanol. The nanoparticles produced were then functionalized with a
bifunctional ligand (composed of both dopamine and triphenylphosphonium ion,
as anchor group and targeting agent respectively), which selectively targeted the
mitochondria. The surface-functionalized MoO 3 nanoparticles demonstrated a builtin biomimetic SuOx activity which permitted the intracellular oxidation of sulfite to
sulfate. When chemically stimulated sulfite oxidase overwhelmed cells were treated
with MoO 3 nanoparticles, they recuperated their sulfite oxidase potential in vitro, and
this makes MoO 3 nanoparticles a prospective curative agent for sulfite oxidase deficiency. Additionally, Wang et al. (2015) found that the bovine serum albumin (BSA)stabilized red- or blue-emitting gold nanoclusters (AuNCs) displayed enzyme-like
activity under visible light irradiation. Red-emitting AuNCs were produced by
mixing aqueous 10 mM HAuCl 4 solution to BSA while vigorous stirring, after which
1.0 mol/l NaOH solution was introduced and incubated at 37 °C while vigorous stirring for 24 h which resulted in a change in color from light yellow to deep brown
while for the fabrication of blue-emitting AuNCs, 1.0 mol/l NaOH solution was
replaced by 50 μL of ascorbic acid in process described for red-emitting AuNCs.
The BSA–AuNCs produced better stability in severe conditions when related with
natural enzyme. Photoactivated BSA–AuNCs were designed to fashion a simplistic,
inexpensive and rapid colorimetric assay to sense trypsin via trypsin digestion of
J. A. Elegbede and A. Lateef
assessed in laccase substrates oxidation (Wang et al. 2017b). This synthesized platinum nanozyme demonstrated good stability in the temperature range of 20–90 °C
and pH 3–9, beyond the range for normal laccase. The most proficient was the C 10 -
templated Pt nanozyme (4.6 nm sized) which displayed three times superior affinity
with regard to 2,4-dichlorophenol than natural laccase. DNA-stabilized Pt nanoparticles produced excellent catalytic potentials in substrates oxidation which include
catechol, dopamine, p-phenylenediamine and hydroquinone. In addition, Xu et al.
(2014) described the fabrication of nanoceria with oxidase-like activity wherein a
solution containing a mixture of 1 M cerium (III) nitrate solution and 1.0 M dextran
were added in a dropwise manner to 30.0 ml ammonium hydroxide solution (25%)
which was stirred continuously for 24 h at ambient temperature, then centrifuged and
precipitated. Nucleoside triphosphates (NTPs) were applied to augment the oxidaselike potential of nanoceria, and it was observed that the improvement directly corresponded with the specific type of NTP applied. The enhancement effect was said to be
in consequence of coupling of the oxidative reaction of nanoceria with the hydrolysis
reactions of NTP. And founded on the effectiveness of the NTP-improved oxidaselike potential of nanoceria, series effective colorimetric assays for single-nucleotide
polymorphism (SNP) typing were generated.
The detoxification processes in the mitochondria involve sulfite oxidase, where
defects in the enzyme lead to harsh infant disease resulting in early death with
no capable or cost-effective therapy in view. Ragg et al. (2014) reported that
molybdenum trioxide (MoO 3 ) nanoparticles demonstrated a fundamental biomimetic
sulfite oxidase (SuOx) activity. The molybdenum trioxide nanoparticles was synthesized by dissolving 10.4 mmol of molybdenum powder and H 2 O 2 in distilled
water and cooled to 0 °C. Acetic acid was added dropwise under rigorous stirring eventually leading to creation of a yellow precipitate washed with distilled
water and ethanol. The nanoparticles produced were then functionalized with a
bifunctional ligand (composed of both dopamine and triphenylphosphonium ion,
as anchor group and targeting agent respectively), which selectively targeted the
mitochondria. The surface-functionalized MoO 3 nanoparticles demonstrated a builtin biomimetic SuOx activity which permitted the intracellular oxidation of sulfite to
sulfate. When chemically stimulated sulfite oxidase overwhelmed cells were treated
with MoO 3 nanoparticles, they recuperated their sulfite oxidase potential in vitro, and
this makes MoO 3 nanoparticles a prospective curative agent for sulfite oxidase deficiency. Additionally, Wang et al. (2015) found that the bovine serum albumin (BSA)stabilized red- or blue-emitting gold nanoclusters (AuNCs) displayed enzyme-like
activity under visible light irradiation. Red-emitting AuNCs were produced by
mixing aqueous 10 mM HAuCl 4 solution to BSA while vigorous stirring, after which
1.0 mol/l NaOH solution was introduced and incubated at 37 °C while vigorous stirring for 24 h which resulted in a change in color from light yellow to deep brown
while for the fabrication of blue-emitting AuNCs, 1.0 mol/l NaOH solution was
replaced by 50 μL of ascorbic acid in process described for red-emitting AuNCs.
The BSA–AuNCs produced better stability in severe conditions when related with
natural enzyme. Photoactivated BSA–AuNCs were designed to fashion a simplistic,
inexpensive and rapid colorimetric assay to sense trypsin via trypsin digestion of