Speckled SiO2@Au Core–Shell Particles as Surface Enhanced Raman Scattering Probes

Khurana, Parul; Thatai, Sheenam; Wang, Peijie; Lihitkar, P.B.; Zhang, Lisheng; Fang, Yan; Kulkarni, Sulabha K.

doi:10.1007/s11468-012-9374-0

Cited by 33 publications

(7 citation statements)

References 31 publications

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“…Gold and silver nanoparticles in various morphologies and core–shell structures have proven to be excellent sensors, sometimes achieving molecular-level detection. − SERS harnesses the enhancement due to the electromagnetic field and chemical factors. One can develop simple, robust, sensitive, and inexpensive chemiresistors for practical gas-sensing applications to be used in household, agricultural, or industrial environments.…”

Section: Results and Discussionmentioning

confidence: 99%

Ultrasensitive Gold Nanostar–Polyaniline Composite for Ammonia Gas Sensing

et al. 2015

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Gold in the form of bulk metal mostly does not react with gases or liquids at room temperature. On the other hand, nanoparticles of gold are very reactive and useful as catalysts. The reactivity of nanoparticles depends on the size and the morphology of the nanoparticles. Gold nanostars containing copper have rough surfaces and large numbers of active sites due to tips, sides, corners, and large surface area-to-volume ratios due to their branched morphology. Here the sensitivity of the gold nanostar-polyaniline composite (average size of nanostars ∼170 nm) toward ammonia gas has been investigated. For 100 ppm ammonia, the sensitivity of the composite increased to 52% from a mere 7% value for pure polyaniline. The gold nanostar-polyaniline composite even showed a response time as short as 15 s at room temperature. The gold nanostars act as a catalyst in the nanocomposite. The stability and sensitivity at different concentrations and the selectivity for ammonia gas were also investigated.

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Section: Results and Discussionmentioning

confidence: 99%

Ultrasensitive Gold Nanostar–Polyaniline Composite for Ammonia Gas Sensing

et al. 2015

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“…The former exhibited a much smoother surface, which is consistent with the literature. 28,57,58 After APTES modification, the TEOS silica NPs were also treated to form Au NPs on their surfaces. The TEM image in Figure 5b shows that, although some Au NPs were supported on the silica surface, they tended to aggregate.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Synthesis of Gold Nanoparticles on Rice Husk Silica for Catalysis Applications

Lan

Liu

et al. 2015

Ind. Eng. Chem. Res.

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Catalysts based on gold nanoparticles (Au NPs) have received much attention during the past two decades because of their unique catalytic properties in basic and applied research. Both experimental findings and theoretical predictions show that the size of the Au NPs plays a crucial role in governing their catalytic capability, with smaller Au NPs typically exhibiting higher catalytic performances. Although mesoporous silica has been extensively used as a support for Au NPs, the diffusion of reactants and products in the pores has been a challenge. Herein, we report an alternative silica material, silica NPs from rice husks (RHs), which have a rough surface, as a potential support for Au NPs. Notably, in this study, RH, a byproduct from rice production, was used as the silica source. Silica obtained by calcining HCl-treated RHs was first modified with (3-aminopropyl)triethoxysilane (APTES), which was designed to play two roles: helping the Au precursor (AuCl4 –) absorb onto the silica surface and stabilizing the resultant Au NPs obtained by reducing AuCl4 – using sodium borohydride (NaBH4). Characterization of the nanostructures revealed that the Au NPs formed with a narrow size distribution of ca. 2–4 nm, which is critical for catalytic applications. The reduction of 4-nitrophenol by NaBH4 with RH-silica-supported Au NPs as a catalyst was systematically studied to demonstrate the excellent catalytic performance of the prepared catalyst.

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“…The speckled SiO 2 @Au NCs were synthesized in our three steps procedure reported elsewhere [49]. In first step, the gold seeds with silica particles were prepared.…”

Section: Synthesis Of Sio 2 @Au Nanocompositesmentioning

confidence: 99%