Catechin-capped gold nanoparticles: green synthesis, characterization, and catalytic activity toward 4-nitrophenol reduction

Choi, Yoon–Ho; Choi, Myung-Jin; Cha, Song-Hyun; Kim, Yeong Shik; Cho, Seonho; Park, Youmie

doi:10.1186/1556-276x-9-103

Cited by 50 publications

(31 citation statements)

References 25 publications

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“…Significantly, PAGNPs2 exhibits an excellent catalytic degradation of 4-NP by converting it to 4-AP within 5 min, and this improved catalytic efficacy can be correlated with its particle size. Comparing this catalytic potential of the PAGNPs2 sample with previous reports, there is a report that nanocrystalsupported gold nanoparticles caused the degradation of 4-NP in 14 min (Wu et al, 2014) and, in another study, catechincapped gold nanoparticles have been reported to exhibit the same degradation activity in 30 min (Choi et al, 2014), while our PAGNPs2 sample exhibits better catalytic degradation within 5 min.…”

Section: Catalysissupporting

confidence: 82%

Green-synthesized gold nanoparticles from Plumeria alba flower extract to augment catalytic degradation of organic dyes and inhibit bacterial growth

2016

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Section: Catalysissupporting

confidence: 82%

Green-synthesized gold nanoparticles from Plumeria alba flower extract to augment catalytic degradation of organic dyes and inhibit bacterial growth

2016

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“…Comparing to the extracellular green‐synthesized metallic NPs, the rate constant on ( Pd@Ag ) @Sp ‐5 composites prepared in this study was 66‐fold higher than that of bio‐PdPt NPs (0.0316 min −1 ), 21‐fold higher than of the catechin‐AuNPs (0.091 min −1 ), and 5‐fold higher than that of colloidal protein–Ag NPs (0.39 min −1 ) . In the case of the green biosynthesis method, colloidal stability of metallic NPs is usually ensured through adsorption of biopolymers or biomolecules onto their surface, such as expolysaccharides, proteins, and catechins, which may be disadvantageous for their better catalytic performance. But the Pd@Ag NPs in this research are polymer free because they are electroless deposited, which contributes to the higher catalytic activity.…”

Section: Resultsmentioning

confidence: 77%

Facile Fabrication of Highly Dispersed Pd@Ag Core–Shell Nanoparticles Embedded in Spirulina platensis by Electroless Deposition and Their Catalytic Properties

Sun

Zhang

Sun

et al. 2018

Adv Funct Materials

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Microorganisms are widely used as the biotemplates for producing micro/ nanomaterials owing to their unique features, such as exquisite morphology, renewable, and environmentally friendly. However, mass intracellular synthesis of uniformly dispersed nanoparticles (NPs) inside microorganisms is still challenging, especially in a predictable and controllable manner. Here, a facile and efficiency strategy is proposed to controllably produce highly dispersed and surfactant-free Pd@Ag core-shell NPs within the Spirulina platensis (Sp.) cells. In this approach, the Sp. cells' permeability is enhanced by the hydrochloric acid treatment first, which enables the Pd NPs penetrate the cell envelope and distribute uniformly inside the cells, and then they can work as the catalytic seeds for the following electroless silver deposition, resulting in the intracellular fabrication of Pd@Ag core-shell NPs with no agglomeration. The Pd@Ag NPs show excellent catalytic activity (turnover frequency is up to 2893 h −1 for the 6.32 nm Pd@Ag NPs), good stability, and recyclability toward the 4-nitrophenol reductions. The excellent properties are attributed to the asymmetrical core-shell structure, small size, and good dispersion of Pd@Ag NPs. Due to its facility, cost-effectiveness, and versatility, this method can be expanded to other microorganisms, so it opens tremendous opportunities for various metallic nanoparticles intracellular synthesis as well as the practical application.

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“…)0.075 (2.22 equiv. )[28]7 Bupleurum falcatum root extract10.5 ± 2.3Spherical0.82 × 10 -3 0.077 (100 equiv. )0.1 (1.43 equiv.…”

Section: Resultsmentioning

confidence: 99%

Catalytic reduction of 4-nitrophenol with gold nanoparticles synthesized by caffeic acid

et al. 2017

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In this study, various concentrations of caffeic acid (CA) were used to synthesize gold nanoparticles (CA-AuNPs) in order to evaluate their catalytic activity in the 4-nitrophenol reduction reaction. To facilitate catalytic activity, caffeic acid was removed by centrifugation after synthesizing CA-AuNPs. The catalytic activity of CA-AuNPs was compared with that of centrifuged CA-AuNPs (cf-CA-AuNPs). Notably, cf-CA-AuNPs exhibited up to 6.41-fold higher catalytic activity compared with CA-AuNPs. The catalytic activity was dependent on the caffeic acid concentration, and the lowest concentration (0.08 mM) produced CA-AuNPs with the highest catalytic activity. The catalytic activities of both CA-AuNPs and cf-CA-AuNPs decreased with increasing caffeic acid concentration. Furthermore, a conversion yield of 4-nitrophenol to 4-aminophenol in the reaction mixture was determined to be 99.8% using reverse-phase high-performance liquid chromatography. The product, 4-aminophenol, was purified from the reaction mixture, and its structure was confirmed by 1H-NMR. It can be concluded that the removal of the reducing agent, caffeic acid in the present study, significantly enhanced the catalytic activity of CA-AuNPs in the 4-nitrophenol reduction reaction.

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Catechin-capped gold nanoparticles: green synthesis, characterization, and catalytic activity toward 4-nitrophenol reduction

Cited by 50 publications

References 25 publications

Green-synthesized gold nanoparticles from Plumeria alba flower extract to augment catalytic degradation of organic dyes and inhibit bacterial growth

Green-synthesized gold nanoparticles from Plumeria alba flower extract to augment catalytic degradation of organic dyes and inhibit bacterial growth

Facile Fabrication of Highly Dispersed Pd@Ag Core–Shell Nanoparticles Embedded in Spirulina platensis by Electroless Deposition and Their Catalytic Properties

Catalytic reduction of 4-nitrophenol with gold nanoparticles synthesized by caffeic acid

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