Spectroscopical investigation on colloidal suspensions of diacetylene-capped gold nanoparticles

Alloisio, Marina; Demartini, Anna; Cuniberti, C.; Dellepiane, G.; Muniz‐Miranda, Maurizio; Giorgetti, E.

doi:10.1016/j.vibspec.2007.12.009

Cited by 14 publications

(13 citation statements)

References 11 publications

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“…Our first results in this field are related to the direct synthesis of CDS9-and DS9-coated AuNPs in organic solvents. 12,26 As expected, a better surface coverage was obtained as testified by the investigation of the time-dependence of the photopolymerized forms that could be followed by UV-Vis technique. It was demonstrated that the polymer highly-conjugated blue phase is formed when the particle diameter is around 10 nm and that only for long irradiation times the blue to red phase transition occurs.…”

Section: Sams On Ag and Au Nanostructured Particlessupporting

confidence: 62%

“…It was demonstrated that the polymer highly-conjugated blue phase is formed when the particle diameter is around 10 nm and that only for long irradiation times the blue to red phase transition occurs. 12,17,26 Instead, the red polymer is present at any polymerization time in smaller particles. 17,26 However, it has to be pointed out that organic solvents at prolonged UV irradiation times can induce particle degradation, due to electron photoejection from the gold core.…”

Section: Sams On Ag and Au Nanostructured Particlesmentioning

confidence: 99%

“…12,17,26 Instead, the red polymer is present at any polymerization time in smaller particles. 17,26 However, it has to be pointed out that organic solvents at prolonged UV irradiation times can induce particle degradation, due to electron photoejection from the gold core. 27 Since by using water as the solvent in the nanostructures preparation would eliminate this problem, we adopted a different synthetic strategy with the aim of obtaining stable aqueous suspensions.…”

Section: Sams On Ag and Au Nanostructured Particlesmentioning

confidence: 99%

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Spectroscopical properties of organic/metal nanohybrids

Dellepiane

Cuniberti

Alloisio

et al. 2010

Phys. Chem. Chem. Phys.

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The aim of our work was to prepare stable nanohybrids of controlled size and shape consisting of a noble metal core decorated with polydiacetylenes (PDAs). Due to the combination of the outstanding linear and nonlinear optical properties of the polydiacetylenic chains with the electromagnetic field-enhancing capability of metal nanostructures, these novel composites can find potential application in different fields. In particular, the different colours exhibited by PDAs in relation to the chemical nature of the monomer and the polymerization procedure, as well as in response to environmental perturbations, make them excellent materials for the fabrication of sensing devices. On the basis of our previous work on PDA self-assembled monolayers on flat metal surfaces, the results of which are briefly reported, we prepared differently-shaped gold and silver nanocores (spheres, cages) coated with various diacetylenic monomers having end-groups able to firmly anchor to the metal surface. These nanohybrids exhibit in aqueous colloidal solution an enhanced photochemical polymerization monitored step by step with UV-Vis and SERS techniques. It is shown that in these stable assemblies an intra-particle polymerization takes place and that the dominant PDA form is conditioned by the core size and geometry. While the nanoparticles are SERS active in the visible, the nanocages should be excellent SERS substrates from the visible to the near infrared regions.

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Section: Sams On Ag and Au Nanostructured Particlessupporting

confidence: 62%

Section: Sams On Ag and Au Nanostructured Particlesmentioning

confidence: 99%

Section: Sams On Ag and Au Nanostructured Particlesmentioning

confidence: 99%

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Spectroscopical properties of organic/metal nanohybrids

Dellepiane

Cuniberti

Alloisio

et al. 2010

Phys. Chem. Chem. Phys.

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“…Marina Alloisio and co-researchers found that the final supramolecular architecture of colloids is the arrangement of the PCDA within the single bilayer [ 19 ]. An AgNP forms a sphere-like structure surrounded by PDA because functional groups incorporated between AgNPs have high affinities for the carboxylic groups in PDA [ 32 ].…”

Section: Resultsmentioning

confidence: 99%

Novel Color Change Film as a Time–Temperature Indicator Using Polydiacetylene/Silver Nanoparticles Embedded in Carboxymethyl Cellulose

et al. 2020

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Time–temperature indicators (TTIs) can be important tools in product applications to monitor food quality losses, especially for fruits and vegetables. In this context, the effects of silver nanoparticles (AgNPs) and glycerol on the color change of polydiacetylene/AgNPs (PDA/AgNPs) embedded in carboxymethyl cellulose (CMC) film as time–temperature indicators (TTIs) were investigated. A CMC film prepared with 30 mg/L AgNPs and a 1:3 (v/v) PDA:AgNP ratio exhibited a faster color change than under other conditions. At 35 °C, the films with PDA/AgNPs changed color from purplish-blue to purple and purple to reddish-purple over time due to the higher thermal conductivity of AgNPs and larger PDA surface area exposed to specific temperatures. The total color difference (TCD) of PDA/AgNP-embedded CMC film directly changed with regard to time and temperature. However, adding glycerol to the system resulted in a symmetrical chemical structure, a factor that delayed the color change. Scanning electron micrographs showed AgNPs embedded in the CMC films. Transmission electron micrographs indicated a core-shell structure of PDA/AgNP vesicles in the CMC matrix. PDA/AgNP vesicles were confirmed by second derivative Fourier transform infrared spectroscopy, with a new peak at 1390–1150 cm−1. The kinetics of TTIs from PDA/AgNP-embedded CMC films yielded an activation energy of 58.70 kJ/mol.

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“…11,13 –21 These naturally occurring antioxidants have been proved to be nontoxic to living organisms and the environment. 1,22 –33 We report the utility of Azolla as reducing agents in the reduction of Au salts to corresponding Au NPs. Azolla (mosquito fern, duckweed fern, fairy moss, and water fern) is a genus of seven species of aquatic ferns, the only genus in the family Azollaceae.…”

Section: Introductionmentioning

confidence: 97%

A Simple, Rapid, and Green Synthesis of Capped Gold Nanospheres and Nanorods Using Aqueous Extract of Azolla

Singh

2013

International Journal of Green Nanotechnology

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In the last few decades, an increasing commercial demand for metal nanoparticles is found due to their numerous applications in various fields such as electronics, catalysis in organic synthesis, material chemistry, energy, and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques, wherein the chemicals used are quite harmful and flammable. Herein, we reported a cheap and environment-friendly procedure for the synthesis of capped gold nanoparticles of different shapes from aqueous solution of tetrachloroauric acid (HAuCl4) using aqueous extract of Azolla pinnata, blue-green algae used as a reducing as well as capping agent. The so-prepared gold nanoparticles were well characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), and quasi-elastic light scattering (QELS) techniques. The TEM showed nearly uniform distribution of the particles in water, which is again confirmed by QELS. This is for the first time that aqueous extract of A. pinnata was used for the synthesis of gold nanoparticles.

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Spectroscopical investigation on colloidal suspensions of diacetylene-capped gold nanoparticles

Cited by 14 publications

References 11 publications

Spectroscopical properties of organic/metal nanohybrids

Spectroscopical properties of organic/metal nanohybrids

Novel Color Change Film as a Time–Temperature Indicator Using Polydiacetylene/Silver Nanoparticles Embedded in Carboxymethyl Cellulose

A Simple, Rapid, and Green Synthesis of Capped Gold Nanospheres and Nanorods Using Aqueous Extract of Azolla

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