101
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Moshe AB, Markovich G. Chiral LigandInduced Circular Dichroism in Excitonic Absorption of Colloidal Quantum Dots. Isr J Chem 2012. [DOI: 10.1002/ijch.201200070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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102
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Ben-Moshe A, Govorov AO, Markovich G. Enantioselective Synthesis of Intrinsically Chiral Mercury Sulfide Nanocrystals. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201207489] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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103
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Ben-Moshe A, Govorov AO, Markovich G. Enantioselective Synthesis of Intrinsically Chiral Mercury Sulfide Nanocrystals. Angew Chem Int Ed Engl 2012; 52:1275-9. [DOI: 10.1002/anie.201207489] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 11/07/2012] [Indexed: 11/10/2022]
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104
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Yan W, Xu L, Xu C, Ma W, Kuang H, Wang L, Kotov NA. Self-assembly of chiral nanoparticle pyramids with strong R/S optical activity. J Am Chem Soc 2012; 134:15114-21. [PMID: 22900978 DOI: 10.1021/ja3066336] [Citation(s) in RCA: 272] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chirality at the nanometer scale represents one of the most rapidly developing areas of research. Self-assembly of DNA-nanoparticle (NP) hybrids enables geometrically precise assembly of chiral isomers. The concept of a discrete chiral nanostructure of tetrahedral shape and topology fabricated from four different NPs located in the corners of the pyramid is fundamental to the field. While the first observations of optical activity of mixed pyramidal assemblies were made in 2009 (Chen, W.; Nano Lett. 2009, 9, 2153-2159), further studies are difficult without finely resolved optical data for precisely organized NP pyramidal enantiomers. Here we describe the preparation of a family of self-assembled chiral pyramids made from multiple metal and/or semiconductor NPs with a yield as high as 80%. Purposefully made R- and S-enantiomers of chiral pyramids with four different NPs from three different materials displayed strong chiroptical activity, with anisotropy g-factors as high as 1.9 × 10(-2) in the visible spectral range. Importantly, all NP constituents contribute to the chiroptical activity of the R/S pyramids. We were able to observe three different circular dichroism signals in the range of 350-550 nm simultaneously. They correspond to the plasmonic oscillations of gold, silver, and bandgap transitions of quantum dots. Tunability of chiroptical bands related to these transitions is essential from fundamental and practical points of view. The predictability of optical properties of pyramids, the simplicity of their self-assembly in comparison with lithography, and the possibility for polymerase chain reaction-based automation of their synthesis are expected to facilitate their future applications.
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Affiliation(s)
- Wenjing Yan
- School of Food Science and Technology, State Key Lab of Food Science and Technology, Jiangnan University, Wuxi, JiangSu 214122, People's Republic China
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105
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Govorov AO, Fan Z. Theory of Chiral Plasmonic Nanostructures Comprising Metal Nanocrystals and Chiral Molecular Media. Chemphyschem 2012; 13:2551-60. [DOI: 10.1002/cphc.201100958] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Indexed: 11/05/2022]
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106
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Nakanishi T, Naito M, Takeoka Y, Matsuura K. Versatile self-assembled hybrid systems with exotic structures and unique functions. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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107
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Mansfeld D, Miersch L, Rüffer T, Schaarschmidt D, Lang H, Böhle T, Troff RW, Schalley CA, Müller J, Mehring M. From {Bi22O26} to Chiral Ligand-Protected {Bi38O45}-Based Bismuth Oxido Clusters. Chemistry 2011; 17:14805-10. [DOI: 10.1002/chem.201102437] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Indexed: 11/09/2022]
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108
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Moshe AB, Szwarcman D, Markovich G. Size dependence of chiroptical activity in colloidal quantum dots. ACS NANO 2011; 5:9034-43. [PMID: 21967095 DOI: 10.1021/nn203234b] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The synthesis of chiral penicillamine-capped CdS and CdSe quantum dots (QDs) was adjusted to control the size of the nanoparticles. This, together with size separation, allowed for simultaneous tuning of absorption, circular dichroism (CD), and fluorescence on a wide wavelength range. Band edge transitions were accompanied by circular dichroism peaks which red-shifted together with the increase in particle size. The clear correlation between absorption and CD bands as well as between absorption bands and size in semiconductor QDs was used to derive an experimental scaling law for optical activity. The decrease in the intensity of circular dichroism-to-absorption ratio (dissymmetry) with the increase in particle size was stronger than linear, probably exponential. In addition, strong material type dependence was observed. The CD line shape appeared to be sensitive to the nature of the transition and may thus serve as a tool for sorting out the electronic states of the QDs. Fluorescence-detected circular dichroism (FDCD) was introduced as a new probe of optically active fluorescent nanoparticles. The analysis of the size and material dependence of the chiroptical induction effect leads to the conclusion that it is primarily an electronic interaction effect between the adsorbed chiral molecules and the electron-hole states.
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Affiliation(s)
- Assaf Ben Moshe
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel
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109
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Zhou Y, Zhu Z, Huang W, Liu W, Wu S, Liu X, Gao Y, Zhang W, Tang Z. Optical coupling between chiral biomolecules and semiconductor nanoparticles: size-dependent circular dichroism absorption. Angew Chem Int Ed Engl 2011; 50:11456-9. [PMID: 22113805 DOI: 10.1002/anie.201103762] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Indexed: 11/06/2022]
Affiliation(s)
- Yunlong Zhou
- Laboratory of Nanomaterials, National Center for Nanoscience and Technology, Beijing, P. R. China
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110
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Zhou Y, Zhu Z, Huang W, Liu W, Wu S, Liu X, Gao Y, Zhang W, Tang Z. Optical Coupling Between Chiral Biomolecules and Semiconductor Nanoparticles: Size-Dependent Circular Dichroism Absorption. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201103762] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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111
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Gérard VA, Gun'ko YK, Defrancq E, Govorov AO. Plasmon-induced CD response of oligonucleotide-conjugated metal nanoparticles. Chem Commun (Camb) 2011; 47:7383-5. [PMID: 21617806 DOI: 10.1039/c1cc11083g] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Non-chiral metal nanoparticles conjugated with chiral oligonucleotide molecules demonstrated a circular dichroism (CD) at the plasmonic wavelengths due to aggregation effects.
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Affiliation(s)
- Valérie A Gérard
- School of Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland
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112
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Li Y, Zhou Y, Wang HY, Perrett S, Zhao Y, Tang Z, Nie G. Chirality of Glutathione Surface Coating Affects the Cytotoxicity of Quantum Dots. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201008206] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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113
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Li Y, Zhou Y, Wang HY, Perrett S, Zhao Y, Tang Z, Nie G. Chirality of Glutathione Surface Coating Affects the Cytotoxicity of Quantum Dots. Angew Chem Int Ed Engl 2011; 50:5860-4. [DOI: 10.1002/anie.201008206] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 03/21/2011] [Indexed: 11/06/2022]
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114
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Xia Y, Zhou Y, Tang Z. Chiral inorganic nanoparticles: origin, optical properties and bioapplications. NANOSCALE 2011; 3:1374-82. [PMID: 21301709 DOI: 10.1039/c0nr00903b] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Chirality of inorganic nanoparticles (NPs) is an emerging and hot topic in nanoresearch in the past several years. Many novel and interesting properties of chiral NPs have been explored and studied, which highlight their importance in both fundamental research and potential applications. This review summarizes recent progress in the study of origins, optical properties and bioapplications of chiral NPs, and future developments in this research area are also discussed.
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Affiliation(s)
- Yunsheng Xia
- Laboratory for Nanomaterials, National Center for Nanoscience and Technology, Beijing, 100190, China
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115
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Abstract
AbstractQuantum dots (QDs) are fluorescent semiconductor (e.g. II-VI) nanocrystals, which have a strong characteristic spectral emission. This emission is tunable to a desired energy by selecting variable particle size, size distribution and composition of the nanocrystals. QDs have recently attracted enormous interest due to their unique photophysical properties and range of potential applications in photonics and biochemistry.The main aim of our work is develop new materials based chiral quantum dots (QDs) and establish fundamental principles influencing the structure and properties of chiral QDs. Here we report the quantum efficiency control in cysteine capped CdTe quantum dots (QDs) by varying ratios of enantiomeric stabilizers. We also demonstrate that the circular dichroism (CD) of CdTe QDs can be introduced by utilizing the mixture of penicilamine and cysteine stabilizers of the same chirality. This approach results in QDs with the enhanced CD activity, but causes a decrease in the quantum yield and widening of the emission due to the presence of chiral defects at the nanoparticle surface. We believe that these new QDs could find important applications as fluorescent assays and sensors (or probes) in asymmetric synthesis, catalysis, enantioseparation, biochemical analysis and medical diagnostics.
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116
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Zhou R, Wei KY, Zhao JS, Jiang YB. Alternative chiral thiols for preparation of chiral CdS quantum dots covered immediately by achiral thiols. Chem Commun (Camb) 2011; 47:6362-4. [DOI: 10.1039/c1cc11537e] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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117
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Govorov AO, Gun'ko YK, Slocik JM, Gérard VA, Fan Z, Naik RR. Chiral nanoparticle assemblies: circular dichroism, plasmonic interactions, and exciton effects. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm12345a] [Citation(s) in RCA: 200] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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118
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Oh HS, Liu S, Jee H, Baev A, Swihart MT, Prasad PN. Chiral Poly(fluorene-alt-benzothiadiazole) (PFBT) and Nanocomposites with Gold Nanoparticles: Plasmonically and Structurally Enhanced Chirality. J Am Chem Soc 2010; 132:17346-8. [DOI: 10.1021/ja107064a] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Heong Sub Oh
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, Department of Chemical and Biological Engineering, and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Sha Liu
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, Department of Chemical and Biological Engineering, and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - HongSub Jee
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, Department of Chemical and Biological Engineering, and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Alexander Baev
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, Department of Chemical and Biological Engineering, and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Mark T. Swihart
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, Department of Chemical and Biological Engineering, and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Paras N. Prasad
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, Department of Chemical and Biological Engineering, and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
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119
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Govan JE, Jan E, Querejeta A, Kotov NA, Gun'ko YK. Chiral luminescent CdS nano-tetrapods. Chem Commun (Camb) 2010; 46:6072-4. [PMID: 20652186 DOI: 10.1039/c0cc00930j] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
The utilisation of chiral penicillamine stabilisers allowed the preparation of new water soluble white emitting CdS nano-tetrapods, which demonstrated circular dichroism in the band-edge region of the spectrum.
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Affiliation(s)
- Joseph E Govan
- School of Chemistry, Trinity College Dublin, Dublin 2, Ireland
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120
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Naito M, Iwahori K, Miura A, Yamane M, Yamashita I. Circularly Polarized Luminescent CdS Quantum Dots Prepared in a Protein Nanocage. Angew Chem Int Ed Engl 2010; 49:7006-9. [DOI: 10.1002/anie.201002552] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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121
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Naito M, Iwahori K, Miura A, Yamane M, Yamashita I. Circularly Polarized Luminescent CdS Quantum Dots Prepared in a Protein Nanocage. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002552] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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122
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Zhou Y, Yang M, Sun K, Tang Z, Kotov NA. Similar topological origin of chiral centers in organic and nanoscale inorganic structures: effect of stabilizer chirality on optical isomerism and growth of CdTe nanocrystals. J Am Chem Soc 2010; 132:6006-13. [PMID: 20384329 DOI: 10.1021/ja906894r] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is observed in this study that the chirality of cysteine stabilizers has a distinct effect on both the growth kinetics and the optical properties of CdTe nanocrystals synthesized in aqueous solution. The effect was studied by circular dichroism spectroscopy, temporal UV-vis spectroscopy, photoluminescence spectroscopy, and several other microscopy and spectroscopic techniques including atomic modeling. Detailed analysis of the entirety of experimental and theoretical data led to the hypothesis that the atomic origin of chiral sites in nanocrystals is topologically similar to that in organic compounds. Since atoms in CdTe nanocrystals are arranged as tetrahedrons, chirality can occur when all four atomic positions have chemical differences. This can happen in apexes of nanocrystals, which are the most susceptible to chemical modification and substitution. Quantum mechanical calculations reveal that the thermodynamically preferred configuration of CdTe nanocrystals is S type when the stabilizer is D-cysteine and R type when L-cysteine is used as a stabilizer, which correlates well with the experimental kinetics of particle growth. These findings help clarify the nature of chirality in inorganic nanomaterials, the methods of selective production of optical isomers of nanocrystals, the influence of chiral biomolecules on the nanoscale crystallization, and practical perspectives of chiral nanomaterials for optics and medicine.
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Affiliation(s)
- Yunlong Zhou
- National Centre for Nanoscience and Technology, Beijing 100190, People's Republic of China
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123
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Fan Z, Govorov AO. Plasmonic circular dichroism of chiral metal nanoparticle assemblies. NANO LETTERS 2010; 10:2580-7. [PMID: 20536209 DOI: 10.1021/nl101231b] [Citation(s) in RCA: 259] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We describe from the theoretical point of view a plasmonic mechanism of optical activity in chiral complexes composed of metal nanoparticles (NPs). In our model, the circular dichroism (CD) signal comes from the Coulomb interaction between NPs. We show that the CD spectrum is very sensitive to the geometry and composition of a chiral complex and also has typically both positive and negative bands. In our calculations, the strongest CD signals were found for the helix geometry resembling helical structures of many biomolecules. For chiral tetramers and pyramids, the symmetry of a frame of a complex is very important for the formation of a strong CD response. Chiral natural molecules (peptides, DNA, etc.) often have strong CD signals in the UV range and typically show weak CD responses in the visible range of photon energies. In contrast to the natural molecules, the described mechanism of plasmonic CD is able to create strong CD signals in the visible wavelength range. This plasmonic mechanism offers a unique possibility to design colloidal and other nanostructures with strong optical chirality.
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Affiliation(s)
- Zhiyuan Fan
- Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA
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124
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Seisenbaeva GA, Moloney MP, Tekoriute R, Hardy-Dessources A, Nedelec JM, Gun'ko YK, Kessler VG. Biomimetic synthesis of hierarchically porous nanostructured metal oxide microparticles--potential scaffolds for drug delivery and catalysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9809-9817. [PMID: 20230060 DOI: 10.1021/la1000683] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hierarchically porous hybrid microparticles, strikingly reminiscent in their structure of the silica skeletons of single-cell algae, diatoms, but composed of titanium dioxide, and the chemically bound amphiphilic amino acids or small proteins can be prepared by a simple one-step biomimetic procedure, using hydrolysis of titanium alkoxides modified by these ligands. The growth of the hierarchical structure results from the conditions mimicking the growth of skeletons in real diatoms--the self-assembly of hydrolysis-generated titanium dioxide nanoparticles, templated by the microemulsion, originating from mixing the hydrocarbon solvent and water on action of amino acids as surfactants. The obtained microsize nanoparticle aggregates possess remarkable chemical and thermal stability and are promising substrates for applications in drug delivery and catalysis. They can be provided with pronounced surface chirality through application of chiral modifying ligands. They display also high selectivity in sorption of phosphorylated biomolecules or medicines as demonstrated by (1)H and (31)P NMR studies and by in vitro modeling using (32)P-marked ATP as a substrate. The release of the adsorbed model compounds in an inert medium is a very slow process directed by desorption kinetics. It is enhanced, however, noticeably in contact with biological fluids modeling those of the tissues suffering inflammation, which makes the produced material highly attractive for application in medical implants. The developed synthetic approach has been applied successfully also for the preparation of analogous hybrid microparticles based on zirconium dioxide or aluminum sesquioxide.
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125
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Govorov AO, Fan Z, Hernandez P, Slocik JM, Naik RR. Theory of circular dichroism of nanomaterials comprising chiral molecules and nanocrystals: plasmon enhancement, dipole interactions, and dielectric effects. NANO LETTERS 2010; 10:1374-82. [PMID: 20184381 DOI: 10.1021/nl100010v] [Citation(s) in RCA: 319] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Our calculations show that a nonchiral nanocrystal is able to dramatically change the circular dichroism (CD) of a chiral molecule when the nanocrystal and molecule form a complex and couple via dipole and multipole Coulomb interactions. Plasmon resonances of metal nanocrystals in the nanocrystal-molecule complex result in both the resonant enhancement of CD signals of molecules and the appearance of new spectral structures. Two mechanisms, in which a nanocrystal can influence the CD effect, have been identified. The first mechanism is the plasmon-induced change in the electromagnetic field inside the chiral molecule. The second is the optical absorption of the nanocrystal-molecule complex due to the chiral currents inside the metal nanocrystal induced by the dipole of the chiral molecule. The first mechanism creates a change in the angle between the effective electric and magnetic dipoles of the molecule. This mechanism can lead to symmetry breaking and to a plasmon-induced CD signal of the nonchiral molecule. Both mechanisms create interesting Fano-like shapes in the CD spectra. Importantly, the second mechanism gives the main contribution to the CD signal at the plasmon frequency when the absorption band of the chiral molecule is far from the plasmon resonance. This may happen in many cases since many biomolecules are optically active in the UV range, whereas plasmon resonances in commonly used nanometals are found at longer wavelengths. As concrete examples, the paper describes alpha-helix and calixarene ligand molecules coupled with metal nanocrystals. The above results are also applied to complexes incorporating semiconductor nanocrystals. The results obtained here can be used to design a variety of hybrid nanostructures with enhanced and tailored optical chirality in the visible wavelength range.
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Affiliation(s)
- Alexander O Govorov
- Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA.
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126
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Sánchez-Castillo A, Noguez C, Garzón IL. On the Origin of the Optical Activity Displayed by Chiral-Ligand-Protected Metallic Nanoclusters. J Am Chem Soc 2010; 132:1504-5. [DOI: 10.1021/ja907365f] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ariadna Sánchez-Castillo
- Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México, D.F., México
| | - Cecilia Noguez
- Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México, D.F., México
| | - Ignacio L. Garzón
- Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México, D.F., México
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127
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Nakano Y, Liu Y, Fujiki M. Ambidextrous circular dichroism and circularly polarised luminescence from poly(9,9-di-n-decylfluorene) by terpene chirality transfer. Polym Chem 2010. [DOI: 10.1039/b9py00288j] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Solvent chirality transfer using enantiomeric pairs of limonene and α-pinene allowed for the successful production of ambidextrous CD-/CPL-active polyfluorene aggregates from achiral polyfluorenes at 25 °C in a few minutes.
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Affiliation(s)
- Yoko Nakano
- Graduate School of Materials Science
- Nara Institute of Science and Technology
- Ikoma
- Japan
| | - Yang Liu
- Suzhou Institute of Nano-tech and Nano-bionics (SINANO)
- Chinese Academy of Sciences
- Dushu Lake Higher Education Town
- Suzhou 215125
- China
| | - Michiya Fujiki
- Graduate School of Materials Science
- Nara Institute of Science and Technology
- Ikoma
- Japan
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128
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Sangthong W, Limtrakul J, Illas F, Bromley ST. Persistence of magic cluster stability in ultra-thin semiconductor nanorods. NANOSCALE 2010; 2:72-77. [PMID: 20648366 DOI: 10.1039/b9nr00282k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The progression from quasi zero-dimensional (Q0D) nanoclusters to quasi one-dimensional (Q1D) nanorods, and, with increasing length, to nanowires, represents the most conceptually fundamental transition from the nanoscale to bulk-like length scales. This dimensionality crossover is particularly interesting, both scientifically and technologically, for inorganic semiconducting (ISC) materials, where striking concomitant changes in optoelectronic properties occur.(1,2) Such effects are most pronounced for ultra-thin(3) ISC nanorods/nanowires, where the confining and defective nature of the atomic structure become key. Although experiments on ISC materials in this size regime have revealed especially stable (or "magic") non-bulk-like Q0D nanoclusters,(4,5) all ISC Q1D nanostructures have been reported as having structures corresponding to bulk crystalline phases. For two important ISC materials (CdS and CdSe) we track the Q0D-to-Q1D transition employing state-of-the-art electronic structure calculations demonstrating an unexpected persistence of magic cluster stability over the bulk-like structure in ultra-thin nanorods up to >10 nm in length. The transition between the magic-cluster-based and wurtzite nanorods is found to be accompanied by a large change in aspect ratio thus potentially providing a route to nano-mechanical transducer applications.
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Affiliation(s)
- Winyoo Sangthong
- Departament de Química Física & Institut de Química Teòrica i Computacional, Universitat de Barcelona, C/Martí i Franquès 1, Barcelona, Spain
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129
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Gallagher SA, Moloney MP, Wojdyla M, Quinn SJ, Kelly JM, Gun'ko YK. Synthesis and spectroscopic studies of chiral CdSe quantum dots. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/c0jm01185a] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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130
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Kawagoe Y, Fujiki M, Nakano Y. Limonene magic: noncovalent molecular chirality transfer leading to ambidextrous circularly polarised luminescent π-conjugated polymers. NEW J CHEM 2010. [DOI: 10.1039/b9nj00733d] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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131
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Nakashima T, Kobayashi Y, Kawai T. Optical activity and chiral memory of thiol-capped CdTe nanocrystals. J Am Chem Soc 2009; 131:10342-3. [PMID: 19588974 DOI: 10.1021/ja902800f] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CdTe nanocrystals (NCs) passivated with chiral ligands d- and l-cysteinemethylester hydrochloride were prepared and observed to exhibit characteristic CD profiles with symmetrical mirror images depending on the chirality of the capping ligand. The optical activity of CdTe NCs is shown to originate from the distorted CdS shell including chiral capping molecules. The chirality of the NC surface is maintained even after ligand exchange with an achiral thiol, providing an unprecedented chiral memory effect.
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Affiliation(s)
- Takuya Nakashima
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
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Qin W, Li X, Qi J. Experimental and theoretical investigation of the catalytic ozonation on the surface of NiO-CuO nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8001-8011. [PMID: 19466811 DOI: 10.1021/la900476m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
NiO-CuO nanoparticles prepared by the sol-gel method were used as catalyst for the degradation of dichloroacetic acid by ozone. Catalyst samples were characterized by measuring the specific area (SBET), X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The catalytic activity of NiO-CuO nanoparticles was investigated for the removal of dichloroacetic acid in aqueous solutions, using different experimental conditions like catalyst dose, initial reaction temperature, and pH have been examined. Ozonation processes were significantly influenced by tert-butyl alcohol, which confirmed that NiO-CuO catalytic ozonation follows a radical-type mechanism, which the hydroxyl radicals were truly identified by spin-trapping/electron spin resonance (EPR) technique and density functional theory (DFT) calculation. In our DFT calculation, we illustrated the atomistic details with three surface models of NiO-CuO nanoparticle and presented a mechanism depicting how an ozone molecule interacted with the surface and how hydroxyl radicals were generated on the surface with a quantitative and qualitative discussion including electronic structure characteristics and relative energetic diagrams. We found partial electron transfer from these surfaces to the adsorbed ozone, which directly led to the decomposition of ozone and promoted the generation of superoxide radical ions and hydroxyl radicals. Results suggested that the introduction of NiO-CuO nanoparticles led to violent interaction between ozone and the catalyst surface, hence promoting the decomposition of ozone and the generation of .OH which, in turn, might lead to an increase in their catalytic ozonation efficiency.
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Affiliation(s)
- Wu Qin
- Department of Chemistry, Harbin Institute of Technology, Harbin, People's Republic of China
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Chen W, Bian A, Agarwal A, Liu L, Shen H, Wang L, Xu C, Kotov NA. Nanoparticle superstructures made by polymerase chain reaction: collective interactions of nanoparticles and a new principle for chiral materials. NANO LETTERS 2009; 9:2153-9. [PMID: 19320495 DOI: 10.1021/nl900726s] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Polymerase chain reaction (PCR) was realized on the surface of gold nanoparticles (NPs) as a tool for self-organization at nanoscale and as a step toward programmable production of sufficient quantities of functional metallic superstructures. The assembly is controlled by varying the density of the primer on the surface of gold NPs and the number of PCR cycles generating a mixture of dimers, trimers, tetramers, etc., with gradually increasing complexity. This process leads to strong chirality of the assemblies arising from the three-dimensional positioning of NPs in space which had never been observed before. A circular dichroism band of the superstructures coincides with the plasmon oscillations of the multi-NP systems of Au colloids. This new collective optical property of NPs embracing the diversity of shapes and diameters in the starting dispersions opens unique opportunities for the development of negative index materials.
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Affiliation(s)
- Wei Chen
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, 48109, USA
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