101
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Porrati F, Sachser R, Huth M. Magnetoresistance of granular Pt-C nanostructures close to the metal-insulator transition. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:085302. [PMID: 24501194 DOI: 10.1088/0953-8984/26/8/085302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate the electrical and magneto-transport properties of Pt-C granular metals prepared by focused electron beam induced deposition. In particular, we consider samples close to the metal-insulator transition obtained from as-grown deposits by means of a low-energy electron irradiation treatment. The temperature dependence of the conductivity shows a σ ∼lnT behavior, with a transition to σ ∼ √T at low temperature, as expected for systems in the strong coupling tunneling regime. The magnetoresistance is positive and is described within the wavefunction shrinkage model, normally used for disordered systems in the weak coupling regime. In order to fit the experimental data, spin-dependent tunneling has to be taken into account. In the discussion we attribute the origin of the spin-dependency to the confinement effects of Pt nano-grains embedded in the carbon matrix.
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Affiliation(s)
- F Porrati
- Physikalisches Institut, Goethe-Universität, Max-von-Laue-Straße 1, D-60438 Frankfurt am Main, Germany
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102
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Zhang C, Li X, Tian C, Yu G, Li Y, Jiang W, Mao C. DNA nanocages swallow gold nanoparticles (AuNPs) to form AuNP@DNA cage core-shell structures. ACS NANO 2014; 8:1130-5. [PMID: 24410162 DOI: 10.1021/nn406039p] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
DNA offers excellent programming properties to nanomaterials syntheses. Host-guest interaction between DNA nanostructures and inorganic nanoparticles (NPs) is of particular interest because the resulting complexes would possess both programming properties intrinsic to DNA and physical properties associated with inorganic NPs, such as plasmonic and magnetic features. Here, we report a class of core-shell complexes (AuNP@DNA cages): hard gold NPs (AuNPs) are encapsulated in geometrically well-defined soft DNA nanocages. The AuNP guest can be further controllably released from the host (DNA nanocages), pointing to potential applications in surface engineering of inorganic NPs and cargo delivery of DNA nanocages.
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Affiliation(s)
- Chuan Zhang
- Department of Chemistry and ‡Markey Center for Structural Biology and Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
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103
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Demortière A, Schaller RD, Li T, Chattopadhyay S, Krylova G, Shibata T, dos Santos Claro PC, Rowland CE, Miller JT, Cook R, Lee B, Shevchenko EV. In Situ Optical and Structural Studies on Photoluminesence Quenching in CdSe/CdS/Au Heterostructures. J Am Chem Soc 2014; 136:2342-50. [DOI: 10.1021/ja4092616] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Arnaud Demortière
- Physics
Department, Illinois Institute of Technology, Chicago, Illinois 60616, United States
| | - Richard D. Schaller
- Department
of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208, United States
| | | | - Soma Chattopadhyay
- CSRRI-IIT, MRCAT, Sector 10, Bldg 433B, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Physics
Department, Illinois Institute of Technology, Chicago, Illinois 60616, United States
| | | | - Tomohiro Shibata
- CSRRI-IIT, MRCAT, Sector 10, Bldg 433B, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Physics
Department, Illinois Institute of Technology, Chicago, Illinois 60616, United States
| | | | - Clare E. Rowland
- Department
of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208, United States
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104
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Perfetti M, Pineider F, Poggini L, Otero E, Mannini M, Sorace L, Sangregorio C, Cornia A, Sessoli R. Grafting single molecule magnets on gold nanoparticles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:323-329. [PMID: 23996936 DOI: 10.1002/smll.201301617] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/05/2013] [Indexed: 06/02/2023]
Abstract
The chemical synthesis and characterization of the first hybrid material composed by gold nanoparticles and single molecule magnets (SMMs) are described. Gold nanoparticles are functionalized via ligand exchange using a tetrairon(III) SMM containing two 1,2-dithiolane end groups. The grafting is evidenced by the shift of the plasmon resonance peak recorded with a UV-vis spectrometer, by the suppression of nuclear magnetic resonance signals, by X-ray photoemission spectroscopy peaks, and by transmission electron microscopy images. The latter evidence the formation of aggregates of nanoparticles as a consequence of the cross-linking ability of Fe4 through the two 1,2-dithiolane rings located on opposite sides of the metal core. The presence of intact Fe4 molecules is directly proven by synchrotron-based X-ray absorption spectroscopy and X-ray magnetic circular dichroism spectroscopy, while a detailed magnetic characterization, obtained using electron paramagnetic resonance and alternating-current susceptibility, confirms the persistence of SMM behavior in this new hybrid nanostructure.
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Affiliation(s)
- Mauro Perfetti
- Department of Chemistry "U. Schiff", Università di Firenze & INSTM RU Firenze, via della Lastruccia 3, 50019, Sesto Fiorentino (FI), Italy
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105
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Physico-Chemical Characteristics of Gold Nanoparticles. GOLD NANOPARTICLES IN ANALYTICAL CHEMISTRY 2014. [DOI: 10.1016/b978-0-444-63285-2.00003-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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106
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Cesca T, Kalinic B, Maurizio C, Scian C, Battaglin G, Mazzoldi P, Mattei G. Near-infrared room temperature luminescence of few-atom Au aggregates in silica: a path for the energy-transfer to Er³⁺ ions. NANOSCALE 2014; 6:1716-1724. [PMID: 24343160 DOI: 10.1039/c3nr04108e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ultra-small molecule-like AuN nanoclusters made by a number of atoms N less than 30 were produced by ion implantation in silica substrates. Their room temperature photoluminescence properties in the visible and near-infrared range have been investigated and correlated with the Er sensitization effects observed in Er-Au co-implanted samples. The intense photoluminescence emission under 488 nm laser excitation occurs in three different spectral regions around 750 nm (band A), 980 nm (band B) and 1150 nm (band C) as a consequence of the formation of discrete energy levels in the electronic structure of the molecule-like AuN nanoclusters. Indeed, energy maxima of bands A and C scale with N(-1/3) as expected for quantum confined systems. Conversely, the energy maximum of band B appears to be almost independent of size, suggesting a contribution of electronic surface states. A clear correlation between the formation of band B in the samples and Er-related photoemission is demonstrated: the band at 980 nm related to AuN nanoclusters resonant with the corresponding Er(3+) absorption level, is suggested as an effective de-excitation channel through which the Au-related photon energy may be transferred from Au nanoclusters to Er ions (either directly or mediated by photon absorption), eventually producing the Er-related infrared emission at 1540 nm.
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Affiliation(s)
- Tiziana Cesca
- Physics and Astronomy Department and CNISM, University of Padova, via Marzolo 8, I-35131 Padova, Italy.
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107
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Crespo P, de la Presa P, Marín P, Multigner M, Alonso JM, Rivero G, Yndurain F, González-Calbet JM, Hernando A. Magnetism in nanoparticles: tuning properties with coatings. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:484006. [PMID: 24201075 DOI: 10.1088/0953-8984/25/48/484006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper reviews the effect of organic and inorganic coatings on magnetic nanoparticles. The ferromagnetic-like behaviour observed in nanoparticles constituted by materials which are non-magnetic in bulk is analysed for two cases: (a) Pd and Pt nanoparticles, formed by substances close to the onset of ferromagnetism, and (b) Au and ZnO nanoparticles, which were found to be surprisingly magnetic at the nanoscale when coated by organic surfactants. An overview of theories accounting for this unexpected magnetism, induced by the nanosize influence, is presented. In addition, the effect of coating magnetic nanoparticles with biocompatible metals, oxides or organic molecules is also reviewed, focusing on their applications.
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108
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van Rhee PG, Zijlstra P, Verhagen TGA, Aarts J, Katsnelson MI, Maan JC, Orrit M, Christianen PCM. Giant magnetic susceptibility of gold nanorods detected by magnetic alignment. PHYSICAL REVIEW LETTERS 2013; 111:127202. [PMID: 24093295 DOI: 10.1103/physrevlett.111.127202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Indexed: 06/02/2023]
Abstract
We have determined the magnetic properties of single-crystalline Au nanorods in solution using an optically detected magnetic alignment technique. The rods exhibit a large anisotropy in the magnetic volume susceptibility (Δχ(V)). Δχ(V) increases with decreasing rod size and increasing aspect ratio and corresponds to an average volume susceptibility (χ(V)), which is drastically enhanced relative to bulk Au. This high value of χ(V) is confirmed by SQUID magnetometry and is temperature independent (between 5 and 300 K). Given this peculiar size, shape, and temperature dependence, we speculate that the enhanced χ(V) is the result of orbital magnetism due to mesoscopic electron trajectories within the nanorods.
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Affiliation(s)
- P G van Rhee
- High Field Magnet Laboratory, Institute of Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, Netherlands
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109
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Li CY, Karna SK, Wang CW, Li WH. Spin polarization and quantum spins in Au nanoparticles. Int J Mol Sci 2013; 14:17618-42. [PMID: 23989607 PMCID: PMC3794745 DOI: 10.3390/ijms140917618] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/01/2013] [Accepted: 08/05/2013] [Indexed: 11/24/2022] Open
Abstract
The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter.
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Affiliation(s)
- Chi-Yen Li
- Department of Physics and Center for Neutron Beam Applications, National Central University, Jhongli 32001, Taiwan.
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110
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Tuboltsev V, Savin A, Pirojenko A, Räisänen J. Magnetism in nanocrystalline gold. ACS NANO 2013; 7:6691-6699. [PMID: 23829643 DOI: 10.1021/nn401914b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
While bulk gold is well known to be diamagnetic, there is a growing body of convincing experimental and theoretical work indicating that nanostructured gold can be imparted with unconventional magnetic properties. Bridging the current gap in experimental study of magnetism in bare gold nanomaterials, we report here on magnetism in gold nanocrystalline films produced by cluster deposition in the aggregate form that can be considered as a crossover state between a nanocluster and a continuous film. We demonstrate ferromagnetic-like hysteretic magnetization with temperature dependence indicative of spin-glass-like behavior and find this to be consistent with theoretical predictions, available in the literature, based on first-principles calculations.
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Affiliation(s)
- Vladimir Tuboltsev
- Division of Materials Physics, Department of Physics, University of Helsinki, PO Box 43, FI-00014 Helsinki, Finland.
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111
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Wang S, Zhao Q, Wei H, Wang JQ, Cho M, Cho HS, Terasaki O, Wan Y. Aggregation-Free Gold Nanoparticles in Ordered Mesoporous Carbons: Toward Highly Active and Stable Heterogeneous Catalysts. J Am Chem Soc 2013; 135:11849-60. [DOI: 10.1021/ja403822d] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Shuai Wang
- The Education Ministry Key Lab of
Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional
Materials, and Department of Chemistry, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Qingfei Zhao
- The Education Ministry Key Lab of
Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional
Materials, and Department of Chemistry, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Huimin Wei
- The Education Ministry Key Lab of
Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional
Materials, and Department of Chemistry, Shanghai Normal University, Shanghai 200234, P. R. China
| | - Jian-Qiang Wang
- Shanghai Synchrotron Radiation Facility
(SSRF), Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, P. R. China
| | - Minhyung Cho
- Graduate School of EEWS (WCU), Korea Advanced Institute of Science and Technology,
Daejeon 305-701, Republic of Korea
| | - Hae Sung Cho
- Graduate School of EEWS (WCU), Korea Advanced Institute of Science and Technology,
Daejeon 305-701, Republic of Korea
| | - Osamu Terasaki
- Graduate School of EEWS (WCU), Korea Advanced Institute of Science and Technology,
Daejeon 305-701, Republic of Korea
| | - Ying Wan
- The Education Ministry Key Lab of
Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional
Materials, and Department of Chemistry, Shanghai Normal University, Shanghai 200234, P. R. China
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112
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Cuadrado R, Puerta JM, Soria F, Cerdá JI. A first principles study of thiol-capped Au nanoparticles: Structural, electronic, and magnetic properties as a function of thiol coverage. J Chem Phys 2013; 139:034319. [DOI: 10.1063/1.4813615] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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113
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Alba Venero D, Fernández Barquín L, Alonso J, Fdez-Gubieda ML, Rodríguez Fernández L, Boada R, Chaboy J. Magnetic disorder in diluted FexM100-x granular thin films (M=Au, Ag, Cu; x < 10 at.%). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:276001. [PMID: 23765439 DOI: 10.1088/0953-8984/25/27/276001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nanogranular thin films of Fe7Au93, Fe7Ag93 and Fe9Cu91 have been sputtered onto Si(100) substrates with the aim of studying the magnetic interactions. X-ray diffraction shows a major noble metal matrix with broad peaks stemming from (111) textured fcc-Au, Ag and Cu. The noble metal forms a nanogranular environment, as confirmed by transmission electron microscopy, with mean particle sizes below 10 nm. The high magnetoresistance (>6%) reveals the existence of Fe nanoparticles. X-ray absorption near edge spectroscopy confirms the presence of a bcc-Fe atom arrangement and some dissolved Fe atoms in the matrix, and XMCD shows the polarization of Au by the Fe nanoparticles. DC-magnetization displays a field-dependent irreversibility produced by the freezing of magnetic nanoparticles into a superspin-glass state. The hysteresis loops remain unsaturated at 5 K and 45 kOe. The coercivity displays a sharp temperature decrease towards a minimum below 50 K, levelling off at higher values, reaching Hc = 200 Oe at 300 K. Annealing of FeAu results in a double-peak zero field cooled magnetization and a slight decrease of the coercivity. The interpretation of the results supports the presence of Fe nanoparticles embedded in the major noble matrix, with some diluted Fe atoms/clusters.
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Affiliation(s)
- D Alba Venero
- CITIMAC Unidad Asociada CSIC, Universidad de Cantabria, E-39005 Santander, Spain.
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114
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McCoy RS, Choi S, Collins G, Ackerson BJ, Ackerson CJ. Superatom paramagnetism enables gold nanocluster heating in applied radiofrequency fields. ACS NANO 2013; 7:2610-2616. [PMID: 23390932 DOI: 10.1021/nn306015c] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The Au102(pMBA)44 nanocluster becomes a superatom paramagnet after chemical oxidation. Solutions of paramagnetic Au102(pMBA)44 heat in an oscillating magnetic field component of an RF field, but not in the electric component. Combined, these experiments suggest that paramagnetic Au102(pMBA)44 heats through interactions of spin magnetic moment with an external oscillating magnetic field. These results may clarify some current controversy regarding gold nanoparticle heating in radiofrequency fields.
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Affiliation(s)
- Ruthanne S McCoy
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80521, United States
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115
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Wang J, Zhang G, Li Q, Jiang H, Liu C, Amatore C, Wang X. In vivo self-bio-imaging of tumors through in situ biosynthesized fluorescent gold nanoclusters. Sci Rep 2013; 3:1157. [PMID: 23362457 PMCID: PMC3557452 DOI: 10.1038/srep01157] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 12/11/2012] [Indexed: 12/15/2022] Open
Abstract
Fluorescence imaging in vivo allows non-invasive tumor diagnostic thus permitting a direct monitoring of cancer therapies progresses. It is established herein that fluorescent gold nanoclusters are spontaneously biosynthesized by cancerous cell (i.e., HepG2, human hepatocarcinoma cell line; K562, leukemia cell line) incubated with micromolar chloroauric acid solutions, a biocompatible molecular Au(III) species. Gold nanoparticles form by Au(III) reduction inside cells cytoplasms and ultimately concentrate around their nucleoli, thus affording precise cell imaging. Importantly, this does not occur in non-cancerous cells, as evidenced with human embryo liver cells (L02) used as controls. This dichotomy is exploited for a new strategy for in vivo self-bio-imaging of tumors. Subcutaneous injections of millimolar chloroauric acid solution near xenograft tumors of the nude mouse model of hepatocellular carcinoma or chronic myeloid leukemia led to efficient biosynthesis of fluorescent gold nanoclusters without significant dissemination to the surrounding normal tissues, hence allowing specific fluorescent self-bio-marking of the tumors.
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Affiliation(s)
- Jianling Wang
- State Key Laboratory of Bioelectronics-Chien-Shiung Wu Lab, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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116
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Zhang H, Goikolea E, Garitaonandia JS, Ortega D, Saito K, Suzuki K. A two-step process for preparation of dodecanethiol-capped Au nanoparticles with room-temperature spontaneous magnetization. NEW J CHEM 2013. [DOI: 10.1039/c3nj00516j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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117
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Khan GG, Sarkar D, Singh AK, Mandal K. Enhanced band gap emission and ferromagnetism of Au nanoparticle decorated α-Fe2O3nanowires due to surface plasmon and interfacial effects. RSC Adv 2013. [DOI: 10.1039/c2ra22578f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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118
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Jiang W, Hibbert DB, Moran G, Herrmann J, Jämting ÅK, Coleman VA. Characterisation of gold agglomerates: size distribution, shape and optical properties. RSC Adv 2013. [DOI: 10.1039/c3ra22727h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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119
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Bartolomé J, Bartolomé F, García LM, Figueroa AI, Repollés A, Martínez-Pérez MJ, Luis F, Magén C, Selenska-Pobell S, Pobell F, Reitz T, Schönemann R, Herrmannsdörfer T, Merroun M, Geissler A, Wilhelm F, Rogalev A. Strong paramagnetism of gold nanoparticles deposited on a Sulfolobus acidocaldarius S layer. PHYSICAL REVIEW LETTERS 2012; 109:247203. [PMID: 23368371 DOI: 10.1103/physrevlett.109.247203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Indexed: 06/01/2023]
Abstract
Magnetic properties of Au nanoparticles deposited on an archaeal S layer are reported. X-ray magnetic circular dichroism and superconducting quantum interference device magnetometries demonstrate that the particles are strongly paramagnetic, without any indication of magnetic blocking down to 16 mK. The average magnetic moment per particle is M(part)=2.36(7) μ(B). This contribution originates at the particle's Au 5d band, in which an increased number of holes with respect to the bulk value is observed. The magnetic moment per Au atom is 25 times larger than any measured in other Au nanoparticles or any other configurations up to date.
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Affiliation(s)
- J Bartolomé
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50009 Zaragoza, Spain.
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120
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Sharma S, Kim B, Lee D. Water-soluble Pd nanoparticles capped with glutathione: synthesis, characterization, and magnetic properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15958-15965. [PMID: 23092154 DOI: 10.1021/la303326u] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The synthesis, characterization, and magnetic properties of water-soluble Pd nanoparticles capped with glutathione are described. The glutathione-capped Pd nanoparticles were synthesized under argon and air atmospheres at room temperature. Whereas the former exhibits a bulklike lattice parameter, the lattice parameter of the latter is found to be considerably greater, indicating anomalous lattice expansion. Comparative structural and compositional studies of these nanoparticles suggest the presence of oxygen in the core lattice when Pd nanoparticles are prepared under an air atmosphere. Both Pd nanoparticles prepared under argon and air show ferromagnetism at 5 K, but the latter exhibits significantly greater coercivity (88 Oe) and magnetization (0.09 emu/g at 50 kOe). The enhanced ferromagnetic properties are explained by the electronic effect of the incorporated oxygen that increases the 4d density of holes at the Pd site and localizes magnetic moments.
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Affiliation(s)
- Sachil Sharma
- Department of Chemistry, Yonsei University, Seoul 120-749, Korea
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121
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Xu J, Hu J, Quan B, Wei Z. Decorating polypyrrole nanotubes with au nanoparticles by an in situ reduction process. Macromol Rapid Commun 2012; 30:936-40. [PMID: 21706552 DOI: 10.1002/marc.200800764] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Au nanoparticle-decorated polypyrrole nanotubes (defined as PPy/Au nanocomposites) are prepared by an in situ reduction process. Polypyrrole (PPy) nanotubes are prepared by a self-degraded template method, and Au nanoparticles are deposited in situ by the reduction of HAuCl(4) . The size and uniformity of the Au nanoparticles that decorate the PPy nanotubes can be controlled by adjusting the experimental conditions, such as the stabilizers used and the reaction temperature. The morphologies and optical properties of the nanocomposites have been characterized by scanning electron microscopy, transmission electron microscopy, UV-vis, and FT-IR spectroscopy. Conductivity measurements show that the conductivities of the nanocomposites decrease with a decrease of temperature, and the conductivity-temperature relationship obeys the quasi-one dimensional variable range hopping model.
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Affiliation(s)
- Jingjing Xu
- National Center for Nanoscience and Technology, Beijing 100190; P. R. China; Graduate School of the Chinese Academy of Sciences, Beijing, 100039, P. R. China
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122
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Nealon GL, Donnio B, Greget R, Kappler JP, Terazzi E, Gallani JL. Magnetism in gold nanoparticles. NANOSCALE 2012; 4:5244-58. [PMID: 22814797 DOI: 10.1039/c2nr30640a] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Gold nanoparticles currently elicit an intense and very broad research activity because of their peculiar properties. Be it in catalysis, optics, electronics, sensing or theranostics, new applications are found daily for these materials. Approximately a decade ago a report was published with magnetometry data showing that gold nanoparticles, most surprisingly, could also be magnetic, with features that the usual rules of magnetism were unable to explain. Many ensuing experimental papers confirmed this observation, although the reported magnetic behaviours showed a great variability, for unclear reasons. In this review, most of the experimental facts pertaining to "magnetic gold" are summarized. The various theories put forth for explaining this unexpected magnetism are presented and discussed. We show that despite much effort, a satisfying explanation is still lacking and that the field of hypotheses should perhaps be widened.
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Affiliation(s)
- Gareth L Nealon
- IPCMS, CNRS, UMR7504, Université de Strasbourg, 23 Rue du Loess, 67034 Strasbourg Cedex 2, France
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123
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Nishigaki JI, Tsunoyama R, Tsunoyama H, Ichikuni N, Yamazoe S, Negishi Y, Ito M, Matsuo T, Tamao K, Tsukuda T. A New Binding Motif of Sterically Demanding Thiolates on a Gold Cluster. J Am Chem Soc 2012; 134:14295-7. [DOI: 10.1021/ja305477a] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jun-ichi Nishigaki
- Department
of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Risako Tsunoyama
- Catalysis Research Center, Hokkaido University, Nishi 10, Kita 21, Sapporo 001-0021,
Japan
| | - Hironori Tsunoyama
- Catalysis Research Center, Hokkaido University, Nishi 10, Kita 21, Sapporo 001-0021,
Japan
| | - Nobuyuki Ichikuni
- Department of Applied
Chemistry
and Biotechnology, Graduate School of Engineering, Chiba University, Inage-ku, Chiba 263-8522, Japan
| | - Seiji Yamazoe
- Department
of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuichi Negishi
- Department of Applied Chemistry,
Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Mikinao Ito
- Functional Elemento-Organic
Chemistry Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tsukasa Matsuo
- Functional Elemento-Organic
Chemistry Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kohei Tamao
- Functional Elemento-Organic
Chemistry Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tatsuya Tsukuda
- Department
of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Catalysis Research Center, Hokkaido University, Nishi 10, Kita 21, Sapporo 001-0021,
Japan
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124
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Gréget R, Nealon GL, Vileno B, Turek P, Mény C, Ott F, Derory A, Voirin E, Rivière E, Rogalev A, Wilhelm F, Joly L, Knafo W, Ballon G, Terazzi E, Kappler JP, Donnio B, Gallani JL. Magnetic Properties of Gold Nanoparticles: A Room-Temperature Quantum Effect. Chemphyschem 2012; 13:3092-7. [DOI: 10.1002/cphc.201200394] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Indexed: 11/11/2022]
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125
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Roy S, Palui G, Banerjee A. The as-prepared gold cluster-based fluorescent sensor for the selective detection of As(III) ions in aqueous solution. NANOSCALE 2012; 4:2734-2740. [PMID: 22422038 DOI: 10.1039/c2nr11786j] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Water-soluble fluorescent gold clusters (AuCs) have been successfully synthesized by a wet-chemical approach at room temperature using a dipeptide l-cysteinyl-l-cysteine. We have followed the core-etching mechanism for the synthesis of the gold clusters. Clusters show the excitation maximum at 300 nm and the emission maximum at 410 nm. These gold clusters show interesting fluorescent properties including large Stoke's shift (110 nm), with a quantum yield of 41.3%, and photochemical stability. Transmission electron microscopic analysis shows that most of these particles are <1.5 nm. These clusters have been applied successfully to develop the new fluorescent sensor for the selective and ultra-sensitive detection of As(III) ions in the presence of other bivalent and trivalent metal ions in aqueous solution with a lower detection limit of 53.7 nM and this is far below the permissible limit (133 nM) of arsenic in drinking water permitted by WHO and USEPA. These gold clusters also show semiconducting behavior.
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Affiliation(s)
- Subhasish Roy
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 32, India
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126
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Reynolds M, Marradi M, Imberty A, Penadés S, Pérez S. Multivalent Gold Glycoclusters: High Affinity Molecular Recognition by Bacterial Lectin PA-IL. Chemistry 2012; 18:4264-73. [DOI: 10.1002/chem.201102034] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Indexed: 11/05/2022]
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127
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Tsukuda T. Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2012. [DOI: 10.1246/bcsj.20110227] [Citation(s) in RCA: 210] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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128
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Turyanska L, Makarovsky O, Patanè A, Kozlova NV, Liu Z, Li M, Mann S. High magnetic field quantum transport in Au nanoparticle-cellulose films. NANOTECHNOLOGY 2012; 23:045702. [PMID: 22214648 DOI: 10.1088/0957-4484/23/4/045702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report the magneto-transport properties of cellulose films comprising interconnected networks of gold nanoparticles (Au NPs). Cellulose is a biopolymer that can be made electrically conducting by cellulose regeneration in Au NP dispersions. The mechanism of electronic conduction in the Au-cellulose films changes from variable range hopping to metallic-like conduction with decreasing resistivity. Our experiments in high magnetic fields (up to 45 T) reveal negative magnetoresistance in the highly resistive films. This is attributed to the spin polarization of the Au NPs and the magnetic field induced suppression of electron spin flips during spin-polarized tunneling in the NP network.
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Affiliation(s)
- L Turyanska
- School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
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129
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Suzuki M, Kawamura N, Miyagawa H, Garitaonandia JS, Yamamoto Y, Hori H. Measurement of a pauli and orbital paramagnetic state in bulk gold using x-ray magnetic circular dichroism spectroscopy. PHYSICAL REVIEW LETTERS 2012; 108:047201. [PMID: 22400883 DOI: 10.1103/physrevlett.108.047201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Indexed: 05/31/2023]
Abstract
We show that bulk gold (Au) exhibits temperature-independent paramagnetism in an external magnetic field by x-ray magnetic circular dichroism spectroscopy at the Au L(2) and L(3) edges. Using the sum-rule analysis, we obtained a magnetic moment of 1.3 × 10(-4) μB/atom in an external magnetic field of 10 T and a paramagnetic susceptibility of 8.9 × 10(-6) for the 5d orbit. The induced paramagnetism in bulk Au is characterized by a large (≈ 30%) orbital contribution. This orbital component was retained even when Au atoms formed nanoparticles, playing an important role in stabilizing the spontaneous spin polarization in the Au nanoparticles.
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Affiliation(s)
- Motohiro Suzuki
- Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.
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130
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Rissner F, Ma Z, Hofmann OT, Slugovc C, Shuai Z, Zojer E. Radical self-assembled monolayers on Au(111) formed by the adsorption of closed-shell molecules. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm15056e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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131
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Samanta PK, Periyasamy G, Manna AK, Pati SK. Computational studies on structural and optical properties of single-stranded DNA encapsulated silver/gold clusters. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm16068d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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132
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Siqueira JR, Gabriel RC, Zucolotto V, Silva ACA, Dantas NO, Gasparotto LHS. Electrodeposition of catalytic and magnetic gold nanoparticles on dendrimer–carbon nanotube layer-by-layer films. Phys Chem Chem Phys 2012; 14:14340-3. [DOI: 10.1039/c2cp42813j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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133
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Wang C, Li J, Amatore C, Chen Y, Jiang H, Wang XM. Gold Nanoclusters and Graphene Nanocomposites for Drug Delivery and Imaging of Cancer Cells. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201105573] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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134
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Wang C, Li J, Amatore C, Chen Y, Jiang H, Wang XM. Gold nanoclusters and graphene nanocomposites for drug delivery and imaging of cancer cells. Angew Chem Int Ed Engl 2011; 50:11644-8. [PMID: 21990208 DOI: 10.1002/anie.201105573] [Citation(s) in RCA: 259] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 09/05/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Chensu Wang
- State Key Lab of Bioelectronics (Chien-Shiung Wu Laboratory), Southeast University, No. 2 Sipailou, Nanjing 210096, China
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135
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Zhu G, Zhang S, Xu Z, Ma J, Shen X. Ultrathin ZnS Single Crystal Nanowires: Controlled Synthesis and Room-Temperature Ferromagnetism Properties. J Am Chem Soc 2011; 133:15605-12. [DOI: 10.1021/ja2049258] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guoxing Zhu
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Shuguang Zhang
- School of Chemical Engineering, Shandong University of Technology, Zibo 255049, China
| | | | | | - Xiaoping Shen
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
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136
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Maitra U, Das B, Kumar N, Sundaresan A, Rao CNR. Ferromagnetism exhibited by nanoparticles of noble metals. Chemphyschem 2011; 12:2322-7. [PMID: 21744458 DOI: 10.1002/cphc.201100121] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 05/07/2011] [Indexed: 11/08/2022]
Abstract
Gold nanoparticles with average diameters in the range 2.5-15 nm, prepared at the organic/aqueous interface by using tetrakis(hydroxymethyl)phosphonium chloride (THPC) as reducing agent, exhibit ferromagnetism whereby the saturation magnetization M(S) increases with decreasing diameter and varies linearly with the fraction of surface atoms. The value of M(S) is higher when the particles are present as a film instead of as a sol. Capping with strongly interacting ligands such as alkane thiols results in a higher M(S) value, which varies with the strength of the metal-sulfur bond. Ferromagnetism is also found in Pt and Ag nanoparticles prepared as sols, and the M(S) values vary as Pt>Au>Ag. A careful study of the temperature variation of the magnetization of Au nanoparticles, along with certain other observations, suggests that small bare nanoparticles of noble metals could indeed possess ferromagnetism, albeit weak, which is accentuated in the presence of capping agents, specially alkane thiols which form strong metal-sulfur bonds.
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Affiliation(s)
- Urmimala Maitra
- CSIR Centre of Excellence in Chemistry, International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore, India
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137
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Kobayashi K, Nagao T, Ito M. Radial integrals for the magnetic form factor of 5dtransition elements. Acta Crystallogr A 2011; 67:473-80. [PMID: 21844652 DOI: 10.1107/s010876731102633x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 07/02/2011] [Indexed: 11/10/2022] Open
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138
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Volkert AA, Subramaniam V, Ivanov MR, Goodman AM, Haes AJ. Salt-mediated self-assembly of thioctic acid on gold nanoparticles. ACS NANO 2011; 5:4570-80. [PMID: 21524135 PMCID: PMC3125453 DOI: 10.1021/nn200276a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Self-assembled monolayer (SAM) modification is a widely used method to improve the functionality and stability of bulk and nanoscale materials. For instance, the chemical compatibility and utility of solution-phase nanoparticles are often improved using covalently bound SAMs. Herein, solution-phase gold nanoparticles are modified with thioctic acid SAMs in the presence and absence of salt. Molecular packing density on the nanoparticle surfaces is estimated using X-ray photoelectron spectroscopy and increases by ∼20% when molecular self-assembly occurs in the presence versus the absence of salt. We hypothesize that as the ionic strength of the solution increases, pinhole and collapsed-site defects in the SAM are more easily accessible as the electrostatic interaction energy between adjacent molecules decreases, thereby facilitating the subsequent assembly of additional thioctic acid molecules. Significantly, increased SAM packing densities increase the stability of functionalized gold nanoparticles by a factor of 2 relative to nanoparticles functionalized in the absence of salt. These results are expected to improve the reproducible functionalization of solution-phase nanomaterials for various applications.
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Affiliation(s)
| | | | | | | | - Amanda J. Haes
- University of Iowa, Department of Chemistry, Iowa City, Iowa 52242
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139
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Kowlgi KNK, Koper GJM, Picken SJ, Lafont U, Zhang L, Norder B. Synthesis of magnetic noble metal (nano)particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7783-7787. [PMID: 21598929 DOI: 10.1021/la105051v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Noble metal particles can be made strongly ferromagnetic or diamagnetic provided that they are synthesized in a sufficiently strong magnetic field. Here we outline two synthesis methods that are fast, reproducible, and allow broad control over particle sizes ranging from nanometers to millimeters. From magnetometry and light spectroscopy, it appears that the cause of this anomalous magnetism is the surface anisotropy in the noble metal particles induced by the applied magnetic field. This work offers an elegant alternative to composite materials of noble metals and magnetic impurities.
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Affiliation(s)
- Krishna N K Kowlgi
- Self-Assembling Systems, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136 , 2628 BL Delft, The Netherlands
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140
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Mohapatra S, Kumar RK, Maji TK. Green synthesis of catalytic and ferromagnetic gold nanoparticles. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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141
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Orientation and organization of gold nanorods on a substrate using a strong magnetic field: Effect of aspect ratio. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2011.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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142
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Hernando A, Crespo P, García MA. Two dimensional electron gas confined over a spherical surface: Magnetic moment. ACTA ACUST UNITED AC 2011. [DOI: 10.1088/1742-6596/292/1/012005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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143
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Kundu S. Layer-by-layer assembly of thiol-capped au nanoparticles on a water surface and their deposition on H-terminated Si(001) by the Langmuir-Blodgett method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:3930-3936. [PMID: 21370906 DOI: 10.1021/la104306m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A monolayer of dodecanethiol-encapsulated Au nanoparticles when compressed laterally transforms into layer-by-layer assemblies on water surface. These layer-by-layer assemblies of Au nanoparticles have been deposited on H-terminated Si(001) substrates by using one down-up cycle (two strokes) in the Langmuir-Blodgett (LB) method. The transformation from monolayer to layer-by-layer assembly on a water surface is irreversible; i.e., if the compressed film is decompressed the layer-by-layer structure cannot regenerate the monolayer structure. Unlike layer-by-layer growth, only odd numbers of layers grow from the monolayer on the H-terminated Si(001) substrates by using different numbers of down-up cycles. Z-type LB deposition occurs only in the first down-up cycle of the hydrophobic substrate, whereas Y-type LB deposition takes place in the successive cycles. Such layer-by-layer assemblies of Au nanoparticles, which are made on bare silicon surfaces and where thickness can be controlled at the nanoscale level, are very promising for their novel applications in the field of nanoscience.
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Affiliation(s)
- Sarathi Kundu
- Department of Materials Science, S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata 700 098, India.
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144
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Di Ventra M, Pershin YV. Spin physics: DNA spintronics sees the light. NATURE NANOTECHNOLOGY 2011; 6:198-199. [PMID: 21468108 DOI: 10.1038/nnano.2011.48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A thin layer of double-stranded DNA on a gold surface can act as a spin filter.
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145
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Enders A, Skomski R, Honolka J. Magnetic surface nanostructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:433001. [PMID: 21403321 DOI: 10.1088/0953-8984/22/43/433001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Recent trends in the emerging field of surface-supported magnetic nanostructures are reviewed. Current strategies for nanostructure synthesis are summarized, followed by a predominantly theoretical description of magnetic phenomena in surface magnetic structures and a review of experimental research in this field. Emphasis is on Fe- or Co-based nanostructures in various low-dimensional geometries, which are studied as model systems to explore the effects of dimensionality, atomic coordination, chemical bonds, alloying and, most importantly, interactions with the supporting substrate on the magnetism. This review also includes a discussion of closely related systems, such as 3d element impurities integrated into organic networks, surface-supported Fe-based molecular magnets, Kondo systems or 4d element nanostructures that exhibit emergent magnetism, thereby bridging the traditional areas of surface science, molecular physics and nanomagnetism.
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Affiliation(s)
- A Enders
- Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588, USA.
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146
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Rao TUB, Nataraju B, Pradeep T. Ag9 Quantum Cluster through a Solid-State Route. J Am Chem Soc 2010; 132:16304-7. [DOI: 10.1021/ja105495n] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Thumu Udaya B. Rao
- DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Bodappa Nataraju
- DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Thalappil Pradeep
- DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India
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147
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S.S.R.Kumar C, Mohammad F. Magnetic Gold Nanoshells: Step-wise Changing of Magnetism through Step-wise Biofunctionalization. J Phys Chem Lett 2010; 1:3141-3146. [PMID: 23646236 PMCID: PMC3641784 DOI: 10.1021/jz101202a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report step-wise changing of magnetic behavior of iron oxide core gold shell nanoparticles from super paramagnetic to permanent magnetism at room temperature, on step-wise bio-functionalization with leutenizing hormone and releasing hormone (LHRH) through cysteamine linker. The observed permanent magnetism at room temperature in LHRH-capped gold nanoshells provides opportunities to extend fundamental investigations of permanent magnetism to other novel nanostructures and biofunctionalized nano gold architectures, simultaneously opening the way to newer applications, especially to those in biomedicine.
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Affiliation(s)
- Challa S.S.R.Kumar
- Center for Advanced Microstructures & Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806. USA
| | - Faruq Mohammad
- Center for Advanced Microstructures & Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806. USA
- Environmental Toxicology, Southern University and A&M College, Baton Rouge, LA 70813, USA
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148
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Wang Y, Chen G, Yang M, Silber G, Xing S, Tan LH, Wang F, Feng Y, Liu X, Li S, Chen H. A systems approach towards the stoichiometry-controlled hetero-assembly of nanoparticles. Nat Commun 2010; 1:87. [DOI: 10.1038/ncomms1089] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 09/09/2010] [Indexed: 11/09/2022] Open
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149
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Mari A, Imperatori P, Marchegiani G, Pilloni L, Mezzi A, Kaciulis S, Cannas C, Meneghini C, Mobilio S, Suber L. High yield synthesis of pure alkanethiolate-capped silver nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15561-15566. [PMID: 20822171 DOI: 10.1021/la102062p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
One-phase, one-pot synthesis of Ag(0) nanoparticles capped with alkanethiolate molecules has been optimized to easily achieve a pure product in quantitative yield. We report the synthesis of dodecanethiolate-capped silver particles and the chemophysical, structural, and morphologic characterization performed by way of UV-vis, (1)H NMR, and X-ray photoelectron (XPS) spectroscopies, X-ray powder diffraction (XRD) and X-ray absorption fine structure analysis (XFAS), electron diffraction and high-resolution transmission electron microscopy (HR-TEM), and scanning and transmission electron microscopy (SEM and TEM). Depending on the molar ratio of the reagents (dodecylthiosulphate/Ag(+)), the mean Ag(0) particle size D(XRD) is tuned from 4 to 3 nm with a narrow size distribution. The particles are highly soluble, very stable in organic solvents (hexane, toluene, dichloromethane, etc.), and resistant to oxidation; the hexane solution after one year at room temperature does not show any precipitation or formation of oxidation byproducts.
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Affiliation(s)
- Alessandra Mari
- CNR-Istituto di Struttura della Materia, P.O. Box 10, I-00015 Monterotondo Stazione, Roma, Italy
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150
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