Chitosan-Stabilized Noble Metal Nanoparticles: Study of their Shape Evolution and Post-Functionalization Properties

Noble metal anisotropic nanostructures have achieved a growing interest in both academic and industrial domains mostly because of their shape-dependent plasmonic properties in the near-infrared region. In this paper, gold and gold-silver anisotropic nanostructures were synthesized in very high shape-yields through a wet, seed-mediated approach based on the use of nearly spherical silver nanoparticles as seeds and chitosan as stabilizing agent. Two chitosans of different origin and molecular properties were selected for the synthetic pathway, leading to the formation of variously sized and shaped end products. In detail, quite homogeneous nanoplatelets of about 25-nm size and 7-nm thickness or nearly spherical, highly porous nanocages of about 50-nm size were obtained, depending on the type of polysaccharide employed. The shape transition towards anisotropic morphologies occurred through a slow, spontaneous process, in which the chitosan nature seemed to play a key role. As expected, both nanoplatelets and nanocages exhibit shape-dependent plasmonic features and surface properties tunable for a variety of application fields. To prove this point, the nanostructures were successfully post-functionalized with poly(10,12-pentacosadiynoic acid) (PCDA), a carboxylic-endowed diacetylene able to anchor on noble metal substrates, to obtain versatile, chromic platforms suitable for sensing and spectroscopic purposes.

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Noble Metal Nanoparticles and Their (Bio) Conjugates. II. Preparation

International Journal of Chemistry ◽

10.5539/ijc.v8n1p86 ◽

2016 ◽

Vol 8 (1) ◽

pp. 86

Author(s):

Ignác Capek

Keyword(s):

Surface Functionalization ◽

Near Infrared ◽

Infrared Region ◽

Hybrid Nanoparticles ◽

Noble Metal Nanoparticles ◽

Shell Nanoparticles ◽

Digestive Ripening ◽

Near Infrared Region ◽

Core Shell Nanoparticles ◽

Anisotropic Nanostructures

Hybrid nanoparticles of gold and silver can not only retain the beneficial features of both nanomaterials, but also possess unique advantages (synergism) over the other two types. Novel pseudospherical and anisotropic nanoparticles, bimetallic triangular nanoparticles, and core@shell nanoparticles were prepared by the different procedures for various applications and understanding both the particle evolution (nucleation) and nanoparticle anisotropy. Hybrid nanoparticles of gold and silver are considered to be low in toxicity, and exhibit facile surface functionalization chemistry. Furthermore, their absorption peaks are located in visible and near-infrared region. These nanoparticles provide significant plasmon tunability, chemical and surface modification properties, and significant advances in the growth into anisotropic nanostructures. The photoinduced synthesis can be used to prepare various (sub) nanoparticles and OD and 1D nanoparticles. Ostwald and digestive ripening provided narrower particle size distribution.

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Electrospinning–thermal treatment synthesis: a general strategy to decorate highly porous nanotubes on both internal and external side-walls with metal oxide/noble metal nanoparticles

Nanoscale ◽

10.1039/c3nr34300f ◽

2013 ◽

Vol 5 (7) ◽

pp. 2835 ◽

Cited By ~ 9

Author(s):

Haitao Zhao ◽

Bingan Lu ◽

Jing Xu ◽

Erqing Xie ◽

Taihong Wang ◽

...

Keyword(s):

Thermal Treatment ◽

Metal Oxide ◽

Metal Nanoparticles ◽

Noble Metal ◽

Noble Metal Nanoparticles ◽

General Strategy ◽

Side Walls ◽

Highly Porous

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Organotrialkoxysilane-Functionalized Noble Metal Monometallic, Bimetallic, and Trimetallic Nanoparticle Mediated Non-Enzymatic Sensing of Glucose by Resonance Rayleigh Scattering

Biosensors ◽

10.3390/bios11040122 ◽

2021 ◽

Vol 11 (4) ◽

pp. 122

Author(s):

Prem C. Pandey ◽

Murli Dhar Mitra ◽

Shubhangi Shukla ◽

Roger J Narayan

Keyword(s):

Metal Nanoparticles ◽

Noble Metal ◽

Metallic Nanoparticles ◽

Rayleigh Scattering ◽

Metal Cations ◽

Pd Nanoparticles ◽

Glucose Sensing ◽

Noble Metal Nanoparticles ◽

Resonance Rayleigh Scattering ◽

Gold Silver

Organotrialkoxysilanes like 3-aminopropyltrimethoxysilane (3-APTMS)-treated noble metal cations were rapidly converted into their respective nanoparticles in the presence of 3-glycidoxypropylytrimethoxysilane (3-GPTMS). The micellar activity of 3-APTMS also allowed us to replace 3-GPTMS with other suitable organic reagents (e.g., formaldehyde); this approach has significant advantages for preparing bimetallic and trimetallic analogs of noble metal nanoparticles that display efficient activity in many practical applications. The formation of monometallic gold, silver, and palladium nanoparticles, bimetallic Ag-Pd, and Au-Pd nanoparticles at various ratios of noble metal cations, and trimetallic Ag-Au-Pd nanoparticles were studied; their biocatalytic activity in non-enzymatic sensing of glucose based on monitoring synchronous fluorescence spectroscopy (SFS) was assessed. Of these nanoparticles, Au-Pd made with an 80:20 Au:Pd ratio displayed excellent catalytic activity for glucose sensing. These nanoparticles could also be homogenized with Nafion to enhance the resonance Rayleigh scattering (RRS) signal. In this study, the structural characterization of noble metal nanoparticles as well as bi- and tri-metallic nanoparticles in addition to their use in non-enzymatic sensing of glucose are reported.

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Synthesis of noble metal nanoparticles and their non-ordered superstructures

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2009.0274 ◽

2010 ◽

Vol 368 (1915) ◽

pp. 1385-1404 ◽

Cited By ~ 49

Author(s):

Nadja C. Bigall ◽

Alexander Eychmüller

Keyword(s):

Metal Nanoparticles ◽

Noble Metal ◽

Cost Effective ◽

Noble Metal Nanoparticles ◽

Colloidal Solutions ◽

Short Introduction ◽

The Third ◽

Organic Templates ◽

Gold Silver ◽

The Given

This article highlights our recent work concerning the synthesis of metal nanoparticles and their non-ordered superstructures. After a short introduction, the basic synthetic procedures are explained for the nanoparticles used for the assemblies. Furthermore, a fabrication method is itemized for very monodisperse platinum nanoparticles in aqueous solution ranging in diameter from 10 to 100 nm showing distinct optical properties. The next section deals with the synthesis of non-ordered hydro- and aerogels from the as-prepared sols. Very light large surface materials from gold, silver, platinum and gold–silver and platinum–silver sols can be fabricated with the given method. Another way to ultralight superstructures of noble metal nanoparticles using fungi as templates is described in the third section. Although fungi grow inside the colloidal solutions they can assemble the nanoparticles onto their surfaces. These hybrid systems are thus extremely interesting supported superstructures for applications in heterogeneous catalysis, since the numbers of nanoparticles on the fungus can easily be tuned, and the fabrication process is cost-effective, environmentally friendly and the organic templates can be easily removed by simple combustion for regaining the noble metal.

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Er3+-to-Yb3+ and Pr3+-to-Yb3+ energy transfer for highly efficient near-infrared cryogenic optical temperature sensing

Nanoscale ◽

10.1039/c8nr08348g ◽

2019 ◽

Vol 11 (3) ◽

pp. 833-837 ◽

Cited By ~ 32

Author(s):

Anna M. Kaczmarek ◽

Mariusz K. Kaczmarek ◽

Rik Van Deun

Keyword(s):

Energy Transfer ◽

Temperature Regime ◽

High Performance ◽

Cryogenic Temperature ◽

Near Infrared ◽

Infrared Region ◽

Temperature Sensing ◽

Highly Efficient ◽

Near Infrared Region ◽

Very High

Nanothermometers based on Er3+-to-Yb3+ and Pr3+-to-Yb3+ energy transfer show very high performance in the near-infrared region in the cryogenic temperature regime.

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One-Pot Facile Synthesis of Noble Metal Nanoparticles Supported on rGO with Enhanced Catalytic Performance for 4-Nitrophenol Reduction

Molecules ◽

10.3390/molecules26237261 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7261

Author(s):

Xiaolong Zhang ◽

Shilei Jin ◽

Yuhan Zhang ◽

Liyuan Wang ◽

Yang Liu ◽

...

Keyword(s):

Metal Nanoparticles ◽

Noble Metal ◽

Measurement Techniques ◽

Catalytic Performance ◽

Noble Metal Nanoparticles ◽

Pt Catalyst ◽

One Pot ◽

K Value ◽

Nitrophenol Reduction ◽

Gold Silver

In this study, reduced graphene oxide (rGO)-supported noble metal (gold, silver, and platinum) nanoparticle catalysts were prepared via the one-pot facile co-reduction technique. Various measurement techniques were used to investigate the structures and properties of the catalysts. The relative intensity ratios of ID/IG in rGO/Au, rGO/Ag, rGO/Pt, and GO were 1.106, 1.078, 1.047, and 0.863, respectively. The results showed the formation of rGO and that noble metal nanoparticles were decorated on rGO. Furthermore, the catalytic activities of the designed nanocomposites were investigated via 4-nitrophenol. The catalysts were used in 4-nitrophenol reduction. The catalytic performance of the catalysts was evaluated using the apparent rate constant k values. The k value of rGO/Au was 0.618 min−1, which was higher than those of rGO/Ag (0.55 min−1) and rGO/Pt (0.038 min−1). The result proved that the rGO/Au catalyst exhibited a higher catalytic performance than the rGO/Ag catalyst and the rGO/Pt catalyst. The results provide a facile method for the synthesis of rGO-supported nanomaterials in catalysis.

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