scholarly journals Preparation of Noble-metal Nanoparticles by Microwave-assisted Chemical Reduction and Evaluation as Catalysts for Nitrile Hydrogenation under Ambient Conditions

2019 ◽  
Vol 62 (5) ◽  
pp. 220-227
Author(s):  
Yoshihide NISHIDA ◽  
Yuichiro WADA ◽  
Chandan CHAUDHARI ◽  
Katsutoshi SATO ◽  
Katsutoshi NAGAOKA
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Chemical Reduction ◽  
Noble Metal Nanoparticles ◽  
Ambient Conditions ◽  
Microwave Assisted

Synthesis and characterization of bimetallic noble metal nanoparticles for biomedical applications

MRS Advances ◽  
2016 ◽  
Vol 1 (11) ◽  
pp. 681-691 ◽  
Author(s):  
Prem C. Pandey ◽  
Govind Pandey
Keyword(s):  
Metal Ions ◽  
Prussian Blue ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Time Course ◽  
Bimetallic Nanoparticles ◽  
Reducing Agents ◽  
Noble Metal Nanoparticles ◽  
Ambient Conditions ◽  
Peroxidase Mimetic

ABSTRACTWe report herein a facile approach to synthesize processable bimetallic nanoparticles (Pd-Au/AuPd/Ag-Au/Au-Ag) decorated Prussian blue nanocomposite (PB-AgNP). The presence of cyclohexanone/formaldehyde facilitates the formation of functional bimetallic nanoparticles from 3-aminopropyltrimethoxysilane (3-APTMS) capped desired ratio of hetero noble metal ions. The use of 3-APTMS and cyclohexanone also enables the synthesis of polycrystalline Prussian blue nanoparticles (PBNPs). As synthesized PBNPs, Pd-Au/Au-Pd/Ag-Au/Au-Ag enable the formation of nano-structured composites displaying better catalytic activity than that recorded with natural enzyme. The nanomaterials have been characterized by Uv-Vis, FT-IR and Transmission Electron Microscopy (TEM) with following major findings: (1) 3-APTMS capped noble metal ions in the presence of suitable organic reducing agents i.e.; 3 glycidoxypropyltrimethoxysilane (GPTMS), cyclohexanone and formaldehyde; are converted into respective nanoparticles under ambient conditions, (2) the time course of synthesis and dispersibility of the nanoparticles are found as a function of organic reducing agents, (3) the use of formaldehyde and cyclohexanone in place of GPTMS with 3-APTMS outclasses the other two in imparting better stability of amphiphilic nanoparticles with reduced silanol content, (4) simultaneous synthesis of bimetallic nanoparticles under desired ratio of palladium/gold and silver/ gold cations are recorded, (5) the nanoparticles made from the use of 3-APTMS and cyclohexanone enable the formation of homogeneous nanocomposite with PBNP as peroxidase mimetic representing potential substitute of peroxidase enzyme. The peroxidase mimetic ability has been found to vary as a function of 3-APTMS concentration revealing the potential role of functional metal nanoparticles in bioanalytical applications.

scholarly journals Noble Metal Nanoparticles-Based Colorimetric Biosensor for Visual Quantification: A Mini Review

Chemosensors ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 53 ◽  
Author(s):  
Lu Yu ◽  
Na Li
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Electrostatic Interactions ◽  
Organic Molecules ◽  
Chemical Reduction ◽  
Noble Metal Nanoparticles ◽  
Gold And Silver Nanoparticles ◽  
Local Surface Plasmon Resonance ◽  
Reliable Technique ◽  
Wide Range

Nobel metal can be used to form a category of nanoparticles, termed noble metal nanoparticles (NMNPs), which are inert (resistant to oxidation/corrosion) and have unique physical and optical properties. NMNPs, particularly gold and silver nanoparticles (AuNPs and AgNPs), are highly accurate and sensitive visual biosensors for the analytical detection of a wide range of inorganic and organic compounds. The interaction between noble metal nanoparticles (NMNPs) and inorganic/organic molecules produces colorimetric shifts that enable the accurate and sensitive detection of toxins, heavy metal ions, nucleic acids, lipids, proteins, antibodies, and other molecules. Hydrogen bonding, electrostatic interactions, and steric effects of inorganic/organic molecules with NMNPs surface can react or displacing capping agents, inducing crosslinking and non-crosslinking, broadening, or shifting local surface plasmon resonance absorption. NMNPs-based biosensors have been widely applied to a series of simple, rapid, and low-cost diagnostic products using colorimetric readout or simple visual assessment. In this mini review, we introduce the concepts and properties of NMNPs with chemical reduction synthesis, tunable optical property, and surface modification technique that benefit the development of NMNPs-based colorimetric biosensors, especially for the visual quantification. The “aggregation strategy” based detection principle of NMNPs colorimetric biosensors with the mechanism of crosslinking and non-crosslinking have been discussed, particularly, the critical coagulation concentration-based salt titration methodology have been exhibited by derived equations to explain non-crosslinking strategy be applied to NMNPs based visual quantification. Among the broad categories of NMNPs based biosensor detection analyses, we typically focused on four types of molecules (melamine, single/double strand DNA, mercury ions, and proteins) with discussion from the standpoint of the interaction between NMNPs surface with molecules, and DNA engineered NMNPs-based biosensor applications. Taken together, NMNPs-based colorimetric biosensors have the potential to serve as a simple yet reliable technique to enable visual quantification.

Investigation of Noble Metal Nanoparticles (Ag, Au, Pd, Pt) Produced by Chemical Reduction

2010 ◽  
Vol 659 ◽  
pp. 115-120 ◽  
Author(s):  
Ágnes Bajáki ◽  
János L. Lábár ◽  
Ágnes Csanády ◽  
Olga Geszti ◽  
Hajnalka Hargitai ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Growth Models ◽  
Chemical Reduction ◽  
Particle Size Analysis ◽  
Atomic Scale ◽  
Noble Metal Nanoparticles ◽  
Size Analysis ◽  
Environmental Friendly ◽  
Water Filters

This work describes atomic-scale, crystalline structure and size distribution for noble metal nanoparticles produced by water-based, environmental friendly technologies. The process was developed and implemented to produce noble metal nanoparticles to be used in water filters, sensors and cosmetics. The particles were investigated by TEM methods and particle size analysis. Growth process of the crystallites in sols made by chemical reduction in aqueous solutions is discussed. Comparison with growth models for vacuum deposited thin films is also identified.

Effect of Noble Metal Nanoparticles in SERRS Measurements of Water-Soluble Porphyrins

2015 ◽  
Vol 1088 ◽  
pp. 43-47
Author(s):  
Pavlína Andrýsková ◽  
Karolína Machalová Šišková ◽  
Ariana Fargašová ◽  
Radek Zbořil
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Ag Nanoparticles ◽  
Chemical Reduction ◽  
Resonance Raman Spectroscopy ◽  
Water Soluble ◽  
Noble Metal Nanoparticles ◽  
Surface Enhanced ◽  
Reduction Methods ◽  
Insight Into

Use of the noble metal nanoparticles in the surface-enhanced resonance Raman spectroscopy (SERRS) is a significant part the measurement. These nanoparticles are often used for SERRS measurements of silver nanoparticles prepared by reduction methods. From the literature it is obvious that the most popular methods of preparation of Ag nanoparticles are procedures which are using the chemical reduction and/or laser ablation. In this paper we discuss the comparison of SERRS spectra of water-soluble porphyrins (TTMAPP and TMPyP) in systems with Ag nanoparticles prepared by chemical reduction with sodium borohydride, sodium citrate and glucose. The comparison of different systems gives insight into the option of suitableility of using of nanoparticles with various surface ions in the production of different spectral forms of chosen porphyrins in dependence on their structures.

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