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Ion-shaping of embedded gold hollow nanoshells into vertically aligned prolate morphologies. Sci Rep 2016; 6:21116. [PMID: 26883992 PMCID: PMC4756376 DOI: 10.1038/srep21116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 12/09/2015] [Indexed: 11/08/2022] Open
Abstract
Ion beam shaping is a novel technique with which one can shape nano-structures that are embedded in a matrix, while simultaneously imposing their orientation in space. In this work, we demonstrate that the ion-shaping technique can be implemented successfully to engineer the morphology of hollow metallic spherical particles embedded within a silica matrix. The outer diameter of these particles ranges between 20 and 60 nm and their shell thickness between 3 and 14 nm. Samples have been irradiated with 74 MeV Kr ions at room temperature and for increasing fluences up to 3.8 × 10(14) cm(-2). In parallel, the experimental results have been theoretically simulated by using a three-dimensional code based on the thermal-spike model. These calculations show that the particles undergo a partial melting during the ion impact, and that the amount of molten phase is maximal when the impact is off-center, hitting only one hemisphere of the hollow nano-particle. We suggest a deformation scenario which differs from the one that is generally proposed for solid nano-particles. Finally, these functional materials can be seen as building blocks for the fabrication of nanodevices with really three-dimensional architecture.
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Lu YH, Liou JY, Lin CF, Sun YS. Electrocatalytic activity of a nitrogen-enriched mesoporous carbon framework and its hybrids with metal nanoparticles fabricated through the pyrolysis of block copolymers. RSC Adv 2015. [DOI: 10.1039/c5ra22528k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Small metal NPs at NEMCF exhibit a four-electron transfer pathway, a large kinetic current density and a small onset potential.
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Affiliation(s)
- Yen-Hsing Lu
- Department of Chemical and Materials Engineering
- National Central University
- Taoyuan 32001
- Taiwan
| | - Jiun-You Liou
- Department of Chemical and Materials Engineering
- National Central University
- Taoyuan 32001
- Taiwan
| | - Chien-Fu Lin
- Department of Chemical and Materials Engineering
- National Central University
- Taoyuan 32001
- Taiwan
| | - Ya-Sen Sun
- Department of Chemical and Materials Engineering
- National Central University
- Taoyuan 32001
- Taiwan
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Goodman AM, Cao Y, Urban C, Neumann O, Ayala-Orozco C, Knight MW, Joshi A, Nordlander P, Halas NJ. The surprising in vivo instability of near-IR-absorbing hollow Au-Ag nanoshells. ACS NANO 2014; 8:3222-31. [PMID: 24547810 PMCID: PMC4004326 DOI: 10.1021/nn405663h] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 02/18/2014] [Indexed: 05/17/2023]
Abstract
Photothermal ablation based on resonant illumination of near-infrared-absorbing noble metal nanoparticles that have accumulated in tumors is a highly promising cancer therapy, currently in multiple clinical trials. A crucial aspect of this therapy is the nanoparticle size for optimal tumor uptake. A class of nanoparticles known as hollow Au (or Au-Ag) nanoshells (HGNS) is appealing because near-IR resonances are achievable in this system with diameters less than 100 nm. However, in this study, we report a surprising finding that in vivo HGNS are unstable, fragmenting with the Au and the remnants of the sacrificial Ag core accumulating differently in various organs. We synthesized 43, 62, and 82 nm diameter HGNS through a galvanic replacement reaction, with nanoparticles of all sizes showing virtually identical NIR resonances at ∼800 nm. A theoretical model indicated that alloying, residual Ag in the nanoparticle core, nanoparticle porosity, and surface defects all contribute to the presence of the plasmon resonance at the observed wavelength, with the major contributing factor being the residual Ag. While PEG functionalization resulted in stable nanoparticles under laser irradiation in solution, an anomalous, strongly element-specific biodistribution observed in tumor-bearing mice suggests that an avid fragmentation of all three sizes of nanoparticles occurred in vivo. Stability studies across a wide range of pH environments and in serum confirmed HGNS fragmentation. These results show that NIR resonant HGNS contain residual Ag, which does not stay contained within the HGNS in vivo. This demonstrates the importance of tracking both materials of a galvanic replacement nanoparticle in biodistribution studies and of performing thorough nanoparticle stability studies prior to any intended in vivo trial application.
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Affiliation(s)
- Amanda M. Goodman
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Yang Cao
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Cordula Urban
- Department of Radiology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - Oara Neumann
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Ciceron Ayala-Orozco
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Mark W. Knight
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Amit Joshi
- Department of Radiology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - Peter Nordlander
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Naomi J. Halas
- Department of Chemistry, Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
- Address correspondence to
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