Microalgal Nanobiotechnology and Its Applications—A …
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GSP concentration to produce nanoplates with lateral sizes ranging from nanometers to micrometers. Most recently, green synthesis of AuNPs was reported using
the aqueous extract of microalgae, Nannochloropsis sp and C. vulgaris (Adenigba
et al. 2020). The absorbance spectra of the biogenic AuNPs showed peak at 520 nm
and 535 nm for C. vulgaris (CV–AuNPs) and Nannochloropsis sp (NN–AuNPs),
respectively. They have spherical shape, polydispersed with size ranging from 7
to 20 nm (CV–AuNPs) and 7 to 26 nm (NN-AuNPs). The biosynthesized AuNPs
displayed very considerable affinity to bioremediate lead and zinc from pharmaceutical effluent. Similarly, Omomowo et al. (2020) successfully biosynthesized AuNPs
through the mixture of 90 ml of 1 mM gold chloride with 10 ml aqueous extract of
Neodesmus pupukensis (MG257914) under ambient conditions. The biosynthesized
AuNPs have circular shape with size ranging from 5 to 34 nm. They demonstrated
considerable antimicrobial activity against some pathogenic microorganisms and
strong antioxidant activity against DPPH radicals.
4.3 Others Nanoparticles
Biosynthesis of iron nanoparticles using soil microalgae, Chlorococcum sp. MM11,
and their potential application in chromium remediation was investigated by Subramaniyam et al. (2015). The 0.1 M iron chloride solution was incubated with the
exponentially growing culture of Chlorococcum sp. under shaking and dark conditions for a period of 48 h. Synthesis of nanoiron was confirmed by the transformation
of reddish yellow of the iron chloride solution to yellowish brown colloid. The biosynthesized nanoiron displayed UV maximum absorbance at 291 nm. Characterization
of the biosynthesized nanoiron by DLS and TEM confirmed the synthesis of spherical
nanoiron with 20–50 nm size range. The FTIR analysis confirmed that biomolecules
such as polysaccharides and glycoproteins contents of the algal cell wall function as
the reducing and capping agent for the synthesized nanoiron. The phyco-synthesized
nanoiron showed potential application for the bioremediation of chromium. Moreover, Brayner et al. (2007) reported the intracellular synthesis of platinum and palladium nanoparticles by strains of cyanobacteria. It was hypothesized that nitrogenase produced by the cyanobacteria bioreduced the platinum and palladium ion to
their corresponding nanoparticles. The nanoparticles were discharged into the culture
medium, and they were thereafter became stabilized by polysaccharides.
The biogenic production of cadmium sulfide (CdS) nanoparticles from cell-free
algal extract was investigated by Rao and Pennathur (2017). The cell-free extract of
Chlamydomonas reinhardtii was used to react with cadmium chloride and sodium
sulfide salts at 65 °C for 20 min. The biosynthesized CdS nanoparticles were
obtained by centrifugation at 8720 × g followed by characterization using UV–visible
absorption spectroscopy, HRTEM, and FTIR. The biosynthesized CdS nanoparticles
showed emission peaks at 430 nm and 470 nm. They have spherical morphology with
5 nm average size. They were stable in solution with a zeta potential of −30.7 mV.
The CdS nanoparticles displayed a very remarkable photocatalytic activity as they
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GSP concentration to produce nanoplates with lateral sizes ranging from nanometers to micrometers. Most recently, green synthesis of AuNPs was reported using
the aqueous extract of microalgae, Nannochloropsis sp and C. vulgaris (Adenigba
et al. 2020). The absorbance spectra of the biogenic AuNPs showed peak at 520 nm
and 535 nm for C. vulgaris (CV–AuNPs) and Nannochloropsis sp (NN–AuNPs),
respectively. They have spherical shape, polydispersed with size ranging from 7
to 20 nm (CV–AuNPs) and 7 to 26 nm (NN-AuNPs). The biosynthesized AuNPs
displayed very considerable affinity to bioremediate lead and zinc from pharmaceutical effluent. Similarly, Omomowo et al. (2020) successfully biosynthesized AuNPs
through the mixture of 90 ml of 1 mM gold chloride with 10 ml aqueous extract of
Neodesmus pupukensis (MG257914) under ambient conditions. The biosynthesized
AuNPs have circular shape with size ranging from 5 to 34 nm. They demonstrated
considerable antimicrobial activity against some pathogenic microorganisms and
strong antioxidant activity against DPPH radicals.
4.3 Others Nanoparticles
Biosynthesis of iron nanoparticles using soil microalgae, Chlorococcum sp. MM11,
and their potential application in chromium remediation was investigated by Subramaniyam et al. (2015). The 0.1 M iron chloride solution was incubated with the
exponentially growing culture of Chlorococcum sp. under shaking and dark conditions for a period of 48 h. Synthesis of nanoiron was confirmed by the transformation
of reddish yellow of the iron chloride solution to yellowish brown colloid. The biosynthesized nanoiron displayed UV maximum absorbance at 291 nm. Characterization
of the biosynthesized nanoiron by DLS and TEM confirmed the synthesis of spherical
nanoiron with 20–50 nm size range. The FTIR analysis confirmed that biomolecules
such as polysaccharides and glycoproteins contents of the algal cell wall function as
the reducing and capping agent for the synthesized nanoiron. The phyco-synthesized
nanoiron showed potential application for the bioremediation of chromium. Moreover, Brayner et al. (2007) reported the intracellular synthesis of platinum and palladium nanoparticles by strains of cyanobacteria. It was hypothesized that nitrogenase produced by the cyanobacteria bioreduced the platinum and palladium ion to
their corresponding nanoparticles. The nanoparticles were discharged into the culture
medium, and they were thereafter became stabilized by polysaccharides.
The biogenic production of cadmium sulfide (CdS) nanoparticles from cell-free
algal extract was investigated by Rao and Pennathur (2017). The cell-free extract of
Chlamydomonas reinhardtii was used to react with cadmium chloride and sodium
sulfide salts at 65 °C for 20 min. The biosynthesized CdS nanoparticles were
obtained by centrifugation at 8720 × g followed by characterization using UV–visible
absorption spectroscopy, HRTEM, and FTIR. The biosynthesized CdS nanoparticles
showed emission peaks at 430 nm and 470 nm. They have spherical morphology with
5 nm average size. They were stable in solution with a zeta potential of −30.7 mV.
The CdS nanoparticles displayed a very remarkable photocatalytic activity as they