Gold Nanoparticle Silica Nanopeapods

Cong, Vu Thanh; Ganbold, Erdene‐Ochir; Saha, Joyanta K.; Jang, Joonkyung; Min, Junhong; Choo, Jaebum; Kim, Sehun; Song, Nam Woong; Son, Sang Jun; Lee, Sang Bok; Joo, Sang‐Woo

doi:10.1021/ja411034q

Cited by 97 publications

(69 citation statements)

References 40 publications

(44 reference statements)

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“…We performed dark-field microscopy (DFM) [23] in cancer cells to check the possibility to apply our method under physiological conditions. We used the zeta potentials, transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), UV-Vis absorption spectroscopy, and SERS to characterize the AuNP suspensions.…”

Section: Methodsmentioning

confidence: 99%

Detection of Copper(II) Ions Using Glycine on Hydrazine-Adsorbed Gold Nanoparticles via Raman Spectroscopy

Seo

Joo

2016

Sensors

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A facile, selective, and sensitive detection method for the Cu2+ ions in environmental and biological solutions has been newly developed by observing the unique CN stretching peaks at ~2108 cm−1 upon the dissociative adsorption of glycine (GLY) in hydrazine buffer on gold nanoparticles (AuNPs). The relative abundance of Cu species on AuNPs was identified from X-ray photoelectron spectroscopy analysis. UV-Vis spectra also indicated that the Au particles aggregated to result in the color change owing to the destabilization induced by the GLY-Cu2+ complex. The CN stretching band at ~2108 cm−1 could be observed to indicate the formation of the CN species from GLY on the hydrazine-covered AuNP surfaces. The other ions of Fe3+, Fe2+, Hg2+, Mg2+, Mn2+, Ni2+, Zn2+, Cr3+, Co2+, Cd2+, Pb2+, Ca2+, NH4+, Na+, and K+ at high concentrations of 50 µM did not produce such spectral changes. The detection limit based on the CN band for the determination of the Cu2+ ion could be estimated to be as low as 500 nM in distilled water and 1 µM in river water, respectively. We attempted to apply our method to estimate intracellular ion detection in cancer cells for more practical purposes.

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Section: Methodsmentioning

confidence: 99%

Detection of Copper(II) Ions Using Glycine on Hydrazine-Adsorbed Gold Nanoparticles via Raman Spectroscopy

Seo

Joo

2016

Sensors

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“…3. 27 The SERS spectra were measured by excitation laser source of 632.8 nm. The SERS enhancement factor of p-MBA was calculated using the formula which reported by Gupta and Weimer 30 as: EF (Enhancement factor) ¼ (I surf /N surf ) Â (N Raman /I Raman )…”

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confidence: 99%

Formation of nanogap Au–polysilsesquioxane 1D chains for SERS application

et al. 2014

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Organized assemblies of polysilsesquioxane having specific functional groups were used as templates to synthesise 1D nanochains of Au having 1-2 nm gap silica peapods. The protonated amines in polysilsesquioxanes formed from N- [3-(trimethoxysilyl)propyl]-ethylene diamine bind with AuCl 4 À leading to formation of monodispersed Au nano-chains by auto reduction.Self-assembly and chemical interaction of supramolecular assemblies with complex ions are used to form noble metal nanoparticles with polymer wrapping. 1,2 Self-assembly and transformation of nanoscale objects in various templates were extensively reviewed by S. Mann. 1 The forces that govern the self-assembly can be either electrostatic or hydrophobic interactions. 3 So templates such as synthetic polymers, proteins, DNA or viruses possess distinct chemical structures and provide multiple well dened binding sites for the attachment of nanoparticles. 4,5 Bottom up synthesis of polymer enveloped gold nanoparticles chains using poly acrylic acid based copolymers were recently reported. 6 The well-known chemistry of hydrolysis and condensation of amino silanes to form siloxane network containing amine functionality have been advantageously exploited for the synthesis of noble metal nano sols of Au, Pt, Ag and Pd by Ovadia's group. 7 Attempts by Bharathi et al., have revealed the stabilization of AuCl 4 À in the amino siloxane network at acidic pHs. 8 The interaction of AuCl 4 À with the protonated amine is attributed to the uniform dispersion of the Au colloid prepared by chemical reduction. Attempts to use N-[3-(trimethoxysilyl)propyl]-ethylenediamine (EDAS) instead of 3-aminopropyltrimethoxysilane (APTMS) have also shown to form stable gold sols on reduction with sodium borohydride. Recently, we have reported the use of the Au, Ag and Au-Ag alloy sols stabilized using EDAS for the chemical catalysis of p-nitrophenol to p-aminophenol. The detailed TEM analysis of these Au and Ag sols reveal that the Au and Ag nanoparticles formed were of poly-dispersed spherical particles. 9The formation of higher order nanostructured polysiloxanes was studied extensively by Kaneko et al., 10 preparation of ammonium group containing ladder-like polysilsesquioxanes (PSQs) was reported rst from 3-aminopropyltrimethoxysilane. The sol-gel reactions of APTMS in the presence of hydrochloric acid (HCl) at elevated temperature were known to form PSQ with perfect ladder arrangements. Actual scheme for the formation of hexagonal phase formed by the arrangement of twisted PSQs were discussed in detail. 10 Similar synthesis of rod like PSQs having a diamine namely N-[3-(trimethoxysilyl) propyl]-ethylene diamine (EDAS) was described by the same research group. 11 The optical properties of the Au colloids can be tailored by coating their surfaces with uniform shells made of dielectric materials such as silica. 12 In principle, one can achieve a precise control over the optical properties of these core-shell colloids by ne-tuning the chemical composition, structure, and dimensions of th...

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“…After 3 layers of silica were deposited, the citrate-stabilized gold nanoparticles (AuNPs) were integrated into the pores. It should be noted that the AuNPs were aggregated into gold clusters around the big opening of silica torpedoes by using a repeated wet-dry process 40, 41 . To improve the connetion of the silica layers between the pores and the surface of the template, a polishing step onto the surface of the template was conducted with wet cotton containing alumina powder (average mech size of 30 μm).…”

Section: Resultsmentioning

confidence: 99%

A Light-Activated Explosive Micropropeller

Rao

et al. 2017

Sci Rep

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Self-propelled micro/nanomotors possess tremendous exciting promise in diverse fields. We describe an asymmetric, fuel-free and near-infrared light-powered torpedo micromotor, which is constructed by using a porous membrane-assisted layer-by-layer sol-gel method to form silica multilayer inside the pores, following by the deposition of gold nanoparticles on one end of the pores. In the absence of chemical fuels, the high propulsion of microtorpedoes under illumination of near-infrared light is owing to the photo-thermal effect of gold clusters, generating a thermal gradient inside the microtorpedoes. The speed of microtorpedoes is dependent on the laser powers and media. More interestingly, such fuel free-powered microtorpedoes could explode triggered by higher laser power at the predefined site and thus provide a new platform for future biomedical applications.

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Gold Nanoparticle Silica Nanopeapods

Cited by 97 publications

References 40 publications

Detection of Copper(II) Ions Using Glycine on Hydrazine-Adsorbed Gold Nanoparticles via Raman Spectroscopy

Detection of Copper(II) Ions Using Glycine on Hydrazine-Adsorbed Gold Nanoparticles via Raman Spectroscopy

Formation of nanogap Au–polysilsesquioxane 1D chains for SERS application

A Light-Activated Explosive Micropropeller

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