Synthesis of Contiguous Silica−Gold Core−Shell Structures:  Critical Parameters and Processes

Phonthammachai, Nopphawan; Kah, James Chen Yong; Guo, Jun; Sheppard, Colin J. R.; Olivo, Malini; Mhaisalkar, Subodh; White, Timothy John

doi:10.1021/la703580r

Cited by 77 publications

(88 citation statements)

References 28 publications

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“…In seed-mediated synthesis seeds, which may be small gold nanoparticles or other nanoparticles (e.g. nickel) are pre-formed on the surface of the SiO 2 particles as deposition sites for gold produced by reduction [22,24]. The one-step method is relatively simple, but the surface of the prepared GNSs is rough with relatively poor controllability and reproducibility.…”

Section: Fabrication Of Gnss With Tunable Plasmon Resonancementioning

confidence: 99%

“…The many preparation methods of GNSs can be categorized as one-step methods and seed-mediated methods [22]. In one-step methods gold formed by reduction of Au(III) directly deposits on the surface of SiO 2 particles with or without amination to form GNSs [22,23].…”

Section: Fabrication Of Gnss With Tunable Plasmon Resonancementioning

confidence: 99%

“…In one-step methods gold formed by reduction of Au(III) directly deposits on the surface of SiO 2 particles with or without amination to form GNSs [22,23]. In seed-mediated synthesis seeds, which may be small gold nanoparticles or other nanoparticles (e.g.…”

Section: Fabrication Of Gnss With Tunable Plasmon Resonancementioning

confidence: 99%

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Plasmonic biosensors and nanoprobes based on gold nanoshells

Rao

et al. 2011

Chin. Sci. Bull.

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Gold nanoshells (GNSs), consisting of a dielectric core coated with gold, have gained extensive attention as they show readily tunable optical properties and good biocompatibility. As highly sensitive and label-free optical biosensors with wide applications, GNSs have been investigated in many fields including drug delivery, immunoassay, cancer treatment, biological sensing and imaging. Taking advantage of the adjustability of the local surface plasmon resonance (LSPR) and the sensitivity of the surfaceenhanced Raman scattering (SERS) signal of GNSs, we have developed diverse applications including plasmonic biosensors and nanoprobes based on GNSs. In this review we introduce plasmonic and electromagnetic properties and fabrication methods of GNSs. We describe research progress in recent years, and highlight several applications of GNSs developed by our group. Finally we provide a brief assessment of future development of GNSs as plasmonic materials that can be integrated with complementary analytical techniques. With advances of technology, one-component materials can no longer meet the needs of society. Thus researchers have fabricated composite materials from two or more materials with complementary functions and optimization of performance [1][2][3][4]. In addition, nanomaterials of noble metals have gained widespread attention with their excellent physical and chemical properties and biocompatibility. Gold, as a typical representative of nanomaterials, has become the noble metal with the most dynamic research and development potential. Furthermore, novel core-shell structured nanomaterials with a variety of shapes, structures and/or controllable components have aroused intense interest in recent years. As a result, gold nanoshells (GNSs) have emerged as metal nanocomposite materials of great interest. GNSs containing a spherical dielectric core surrounded by an ultrathin, conductive gold layer not only offer superiority in performance but also great potential for developing simple, fast, and lowcost bioanalytical methods for biosensing and nanoprobes. As a new type of nanocomposite material, GNSs possess many notable features. Their linear optical properties, infrared extinction characteristics, photothermal conversion properties, acoustic properties, cavity absorption and electron dynamics characteristics, make GNSs a focal point of basic and applied research. In addition to tunable LSPR among other features, GNSs show a strong electromagnetic enhancement effect, which makes GNSs a potentially ideal active SERS substrate [5,6]. Research in this area has revealed many new phenomena and raised many new issues, and provided new principles and new methods for nano-characterization technology and sensor technology, which will lead to new types of ultra-high sensitivity sensors for LSPR and SERS. This paper will focus on the fabrication of GNSs and research progress in the field in chemical/biological sensing and surface-enhanced spectroscopy.

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Section: Fabrication Of Gnss With Tunable Plasmon Resonancementioning

confidence: 99%

Section: Fabrication Of Gnss With Tunable Plasmon Resonancementioning

confidence: 99%

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Plasmonic biosensors and nanoprobes based on gold nanoshells

Rao

et al. 2011

Chin. Sci. Bull.

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“…DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES…”

Section: Sponsor/monitor's Report Number(s)mentioning

confidence: 99%

“…Baker; 99.8 %) in a mixture of water (100 mL) [12][13] . After stirring for 10 min, an aliquot (1 %, 2 mL) of HAuCl 4 solution was added.…”

Section: Gold Nanoshell Growthmentioning

confidence: 99%

Metal Nanoshells for Enhanced Solar-to-Fuel Photocatalytic Conversion

Lee¹

2011

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In our preliminary study, we had prepared quaternary semiconductor powder of Ag x In x Zn y S 2x+y , a photocatalysts with a high activity. In this study, we further extended the investigation, changed the amount of indium in a series of solid solutions, and increased the photochemical activity substantially.With little adjustment of the ratios of [In]/[Ag], the hydrogen production rate of the photocatalysts, Ag x In y Zn z S (x+3y+2z)/2 , are significantly improved. The most enhancement of the activity can go up to four times, compared to our first generation photocatalyst. SEM images show that different amount of nonosteps on the surface relate to the ratios of [In]/[Ag]. These edges of nanosteps are considered as the active sites that facilitate the electron-hole separation, leading to higher solar-to-fuel conversion efficiency. The other ingredient, zinc, is used to control the band gap. Both changes of indium and zinc, we maximized the efficiency of this photocatalyst (970 μmol/h·g). In a separate experiment, the photocatalystic reactions were carried out at elevated temperature. The effect of temperature, typically with addition of Ag@Au NPs (nanoparticles) was evaluated. The presence of metal nanoshells can absorb the solar energy in the IR range. However, the broad absorption of metal nanoshells also covered the visible-light region, which decrease the efficiency of the metal sulfide photocatalysts. The incorporation of metal nanoshells, as well as the nanostructure of photocatalyst will be further investigated. IntroductionOf all known renewable energy sources, solar energy stands as the most abundant and readily accessible. Consider, for example, that the amount of solar energy striking the earth every 40 minutes Report Documentation PageForm Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. REPORT DATE SEP 20112. REPORT TYPE Secondly, it was demonstrated that at an elevated temperature, the hydrogen evolution rate is higher. Future study will focus on improving the efficiency of our second-generation photocatalyst, create various core-shell structures, measure the hydrogen production rate, and test the stability of this composite system.

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Gold Nanoshells in Biomedical Applications

Erickson

Tunnell

2009

Nanotechnologies for the Life Sciences

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The sections in this article are Introduction Physical Properties of Gold Nanoshells Overview of General Optical Properties The Physics of Gold Nanoshells The Dielectric Function of Gold The Quasi‐Static Approximation and Conditions for Surface Plasmon Resonance M ie Theory Near‐Field Enhancement Photoluminescence Photo‐Thermal Material Characteristics Synthesis and Bioconjugation Synthesis Bioconjugation: Smarter Nanoshells Biodistribution, Toxicity Profile and Transport Biodistribution Studies Transport Mechanisms Toxicity Biomedical Applications In Vitro Cancer Detection and Imaging In Vivo Detection and Imaging Integrated Cancer Imaging and Therapy Agents In Vitro Studies In Vivo Photothermal Therapy Drug Delivery Tissue Welding Biosensors Absorbance‐Based Biosensing SERS Biosensing Concluding Remarks

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Synthesis of Contiguous Silica−Gold Core−Shell Structures: Critical Parameters and Processes

Cited by 77 publications

References 28 publications

Plasmonic biosensors and nanoprobes based on gold nanoshells

Plasmonic biosensors and nanoprobes based on gold nanoshells

Metal Nanoshells for Enhanced Solar-to-Fuel Photocatalytic Conversion

Gold Nanoshells in Biomedical Applications

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