1
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Nunes PP, Almeida MR, Pacheco FG, Fantini C, Furtado CA, Ladeira LO, Jorio A, Júnior APM, Santos RL, Borges ÁM. Detection of carbon nanotubes in bovine raw milk through Fourier transform Raman spectroscopy. J Dairy Sci 2024; 107:2681-2689. [PMID: 37923204 DOI: 10.3168/jds.2023-23481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
The potential use of carbon-based methodologies for drug delivery and reproductive biology in cows raises concerns about residues in milk and food safety. This study aimed to assess the potential of Fourier transform Raman spectroscopy and discriminant analysis using partial least squares (PLS-DA) to detect functionalized multiwalled carbon nanotubes (MWCNT) in bovine raw milk. Oxidized MWCNT were diluted in milk at different concentrations from 25.00 to 0.01 µg/mL. Raman spectroscopy measurements and PLS-DA were performed to identify low concentrations of MWCNT in milk samples. The PLS-DA model was characterized by the analysis of the variable importance in projection (VIP) scores. All the training samples were correctly classified by the model, resulting in no false-positive or false-negative classifications. For test samples, only one false-negative result was observed, for 0.01 µg/mL MWCNT dilution. The association between Raman spectroscopy and PLS-DA was able to identify MWCNT diluted in milk samples up to 0.1 µg/mL. The PLS-DA model was built and validated using a set of test samples and spectrally interpreted based on the highest VIP scores. This allowed the identification of the vibrational modes associated with the D and G bands of MWCNT, as well as the milk bands, which were the most important variables in this analysis.
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Affiliation(s)
- Philipe P Nunes
- Department of Veterinary Clinic and Surgery, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Mariana R Almeida
- Department of Chemistry, Institute of Exact Science, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Flávia G Pacheco
- Laboratory of Carbon Nanostructure Chemistry, Nuclear Technology Development Center, Belo Horizonte, MG 31270-901, Brazil
| | - Cristiano Fantini
- Department of Physics, Institute of Exact Science, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Clascídia A Furtado
- Laboratory of Carbon Nanostructure Chemistry, Nuclear Technology Development Center, Belo Horizonte, MG 31270-901, Brazil
| | - Luiz O Ladeira
- Department of Physics, Institute of Exact Science, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Ado Jorio
- Department of Physics, Institute of Exact Science, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Antônio P M Júnior
- Department of Veterinary Clinic and Surgery, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Renato L Santos
- Department of Veterinary Clinic and Surgery, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Álan M Borges
- Department of Veterinary Clinic and Surgery, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil.
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2
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Portes A, Nadas R, Jorio A, Ramirez JC. Electro-optical properties of a graphene device on a tip-enhanced Raman spectroscopy system. Opt Lett 2024; 49:871-874. [PMID: 38359204 DOI: 10.1364/ol.512195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/10/2024] [Indexed: 02/17/2024]
Abstract
This paper investigates the impact of graphene on tip-enhanced Raman spectroscopy (TERS) by developing an electromagnetic characterization of the TERS-graphene device system. The study focuses on the interaction between the tip, the gate voltage, and the sample, specifically examining the electromagnetic effects in the system. Employing a finite element method (FEM)-based simulation model, we meticulously dissect the electric field distribution and the Raman amplification when graphene is introduced into the system. Our findings reveal that including graphene results in a marginal reduction in Raman amplification and a negligible variation in the induced charges within the system. To reinforce our simulations, we employ a simplified capacitor model, which corroborates our results, showcasing negligible induced charges and validating the obtained capacitance values. In this manuscript, we also explore the influence of the setup on the electro-optical properties of graphene, revealing a slight variation in conductivity despite strong changes in chemical potential. Overall, this work contributes to understanding TERS's electromagnetic aspects in the presence of graphene.
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3
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Nadas RB, Gadelha AC, Barbosa TC, Rabelo C, de Lourenço E Vasconcelos T, Monken V, Portes AVR, Watanabe K, Taniguchi T, Ramirez JC, Campos LC, Saito R, Cançado LG, Jorio A. Spatially Coherent Tip-Enhanced Raman Spectroscopy Measurements of Electron-Phonon Interaction in a Graphene Device. Nano Lett 2023; 23:8827-8832. [PMID: 37432971 DOI: 10.1021/acs.nanolett.3c00851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
Coherence length (Lc) of the Raman scattering process in graphene as a function of Fermi energy is obtained with spatially coherent tip-enhanced Raman spectroscopy. Lc decreases when the Fermi energy is moved into the neutrality point, consistent with the concept of the Kohn anomaly within a ballistic transport regime. Since the Raman scattering involves electrons and phonons, the observed results can be rationalized either as due to unusually large variation of the longitudinal optical phonon group velocity vg, reaching twice the value for the longitudinal acoustic phonon, or due to changes in the electron energy uncertainty, both properties being important for optical and transport phenomena that might not be observable by any other technique.
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Affiliation(s)
- Rafael Battistella Nadas
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Andreij C Gadelha
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Tiago C Barbosa
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
- Centro de Tecnologia em Nanomateriais e Grafeno, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | | | | | - Vitor Monken
- FabNS, Belo Horizonte, Minas Gerais 31310-260, Brazil
- Programa de Pós-Graduação em Inovação Tecnológica e Propriedade Intelectual, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Ary V R Portes
- Departamento de Engenharia Eletrônica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Kenji Watanabe
- NIMS, 1-2-1 Sengen, Tsukuba-city, Ibaraki 305-0047, Japan
| | | | - Jhonattan C Ramirez
- Departamento de Engenharia Eletrônica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Leonardo C Campos
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
- Centro de Tecnologia em Nanomateriais e Grafeno, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Riichiro Saito
- Department of Physics, Tohoku University, Sendai, 980-8578, Japan
| | - Luiz Gustavo Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
- Programa de Pós-Graduação em Inovação Tecnológica e Propriedade Intelectual, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil
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Gadelha AC, Nguyen VH, Neto EGS, Santana F, Raschke MB, Lamparski M, Meunier V, Charlier JC, Jorio A. Electron-Phonon Coupling in a Magic-Angle Twisted-Bilayer Graphene Device from Gate-Dependent Raman Spectroscopy and Atomistic Modeling. Nano Lett 2022; 22:6069-6074. [PMID: 35878122 DOI: 10.1021/acs.nanolett.2c00905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The importance of phonons in the strong correlation phenomena observed in twisted-bilayer graphene (TBG) at the so-called magic-angle is under debate. Here we apply gate-dependent micro-Raman spectroscopy to monitor the G band line width in TBG devices of twist angles θ = 0° (Bernal), ∼1.1° (magic-angle), and ∼7° (large-angle). The results show a broad and p-/n-asymmetric doping behavior at the magic angle, in clear contrast to the behavior observed in twist angles above and below this point. Atomistic modeling reproduces the experimental observations in close connection with the joint density of electronic states in the electron-phonon scattering process, revealing how the unique electronic structure of magic-angle TBGs influences the electron-phonon coupling and, consequently, the G band line width. Overall, the value of the G band line width in magic-angle TBG is larger when compared to that of the other samples, in qualitative agreement with our calculations.
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Affiliation(s)
- Andreij C Gadelha
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
- Department of Physics, and JILA, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Viet-Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain (UCLouvain), Louvain-la-Neuve 1348, Belgium
| | - Eliel G S Neto
- Physics Institute, Universidade Federal da Bahia, Salvador, Bahia 40170-115 Brazil
| | - Fabiano Santana
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Markus B Raschke
- Department of Physics, and JILA, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Michael Lamparski
- Department of Physics, Applied Physics, and Astronomy, Jonsson Rowland Science Center, Troy, New York 12180-3590, United States
| | - Vincent Meunier
- Department of Physics, Applied Physics, and Astronomy, Jonsson Rowland Science Center, Troy, New York 12180-3590, United States
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain (UCLouvain), Louvain-la-Neuve 1348, Belgium
| | - Ado Jorio
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
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5
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Affiliation(s)
- Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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6
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Pena AP, Almeida RG, Campos JL, Dos Santos HF, da Silva Júnior EN, Jorio A. Raman spectra-based structural classification analysis of quinoidal and derived molecular systems. Phys Chem Chem Phys 2022; 24:1183-1190. [PMID: 34931633 DOI: 10.1039/d1cp04261k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This work reports a classification analysis method based on the vibrational Raman spectra of 38 quinones and related structures, spectrally ordering and classifying the compounds. The molecular systems are relevant for chemical and biological processes, with applications in pharmacology, toxicology and medicine. The classification strategy uses a combination of principal component analysis with K-means clustering methods. Both theoretical simulations and experimental data are analysed, thus establishing their spectral characteristics, as related to their chemical structures and properties. The protocol introduced here should be broadly applicable in other molecular and solid state systems.
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Affiliation(s)
- Arthur P Pena
- Departamento de Física, ICEX, UFMG, Belo Horizonte, MG, 31270-901, Brazil.
| | - Renata G Almeida
- Departamento de Química, ICEX, UFMG, Belo Horizonte, MG, 31270-901, Brazil
| | - João Luiz Campos
- Departamento de Física, ICEX, UFMG, Belo Horizonte, MG, 31270-901, Brazil.
| | | | | | - Ado Jorio
- Departamento de Física, ICEX, UFMG, Belo Horizonte, MG, 31270-901, Brazil.
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Malard LM, Lafeta L, Cunha RS, Nadas R, Gadelha A, Cançado LG, Jorio A. Studying 2D materials with advanced Raman spectroscopy: CARS, SRS and TERS. Phys Chem Chem Phys 2021; 23:23428-23444. [PMID: 34651627 DOI: 10.1039/d1cp03240b] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Raman spectroscopy has been established as a valuable tool to study and characterize two-dimensional (2D) systems, but it exhibits two drawbacks: a relatively weak signal response and a limited spatial resolution. Recently, advanced Raman spectroscopy techniques, such as coherent anti-Stokes spectroscopy (CARS), stimulated Raman scattering (SRS) and tip-enhanced Raman spectroscopy (TERS), have been shown to overcome these two limitations. In this article, we review how useful physical information can be retrieved from different 2D materials using these three advanced Raman spectroscopy and imaging techniques, discussing results on graphene, hexagonal boron-nitride, and transition metal di- and mono-chalcogenides, thus providing perspectives for future work in this early-stage field of research, including similar studies on unexplored 2D systems and open questions.
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Affiliation(s)
- Leandro M Malard
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
| | - Lucas Lafeta
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
| | - Renan S Cunha
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
| | - Rafael Nadas
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
| | - Andreij Gadelha
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
| | - Luiz Gustavo Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 30123-970, Brazil.
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8
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Fonseca EA, Lafeta L, Luiz Campos J, Cunha R, Barbosa A, Romano-Silva MA, Vieira R, Malard LM, Jorio A. Micro-Raman spectroscopy of lipid halo and dense-core amyloid plaques: aging process characterization in the Alzheimer's disease APPswePS1ΔE9 mouse model. Analyst 2021; 146:6014-6025. [PMID: 34505596 DOI: 10.1039/d1an01078f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The deposition of amyloid plaques is considered one of the main microscopic features of Alzheimer's disease (AD). Since plaque formation can precede extensive neurodegeneration and it is the main clinical manifestation of AD, it constitutes a relevant target for new treatment and diagnostic approaches. Micro-Raman spectroscopy, a label-free technique, is an accurate method for amyloid plaque identification and characterization. Here, we present a high spatial resolution micro-Raman hyperspectral study in transgenic APPswePS1ΔE9 mouse brains, showing details of AD tissue biochemical and histological changes without staining. First we used stimulated micro-Raman scattering to identify the lipid-rich halo surrounding the amyloid plaque, and then proceeded with spontaneous (conventional) micro-Raman spectral mapping, which shows a cholesterol and sphingomyelin lipid-rich halo structure around dense-core amyloid plaques. The detailed images of this lipid halo relate morphologically well with dystrophic neurites surrounding plaques. Principal Component Analysis (PCA) of the micro-Raman hyperspectral data indicates the feasibility of the optical biomarkers of AD progression with the potential for discriminating transgenic groups of young adult mice (6-month-old) from older ones (12-month-old). Frequency-specific PCA suggests that plaque-related neurodegeneration is the predominant change captured by Raman spectroscopy, and the main differences are highlighted by vibrational modes associated with cholesterol located majorly in the lipid halo.
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Affiliation(s)
- Emerson A Fonseca
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil. .,Programa de Pós-Graduação em Inovação Tecnológica e Biofarmacêutica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Lucas Lafeta
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
| | - João Luiz Campos
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
| | - Renan Cunha
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
| | - Alexandre Barbosa
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil. .,Departamento de Oftalmologia, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30130-100, Brazil
| | - Marco A Romano-Silva
- Departamento de Saúde Mental, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30130-100, Brazil
| | - Rafael Vieira
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Leandro M Malard
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
| | - Ado Jorio
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil. .,Programa de Pós-Graduação em Inovação Tecnológica e Biofarmacêutica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
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9
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Gadelha AC, Vasconcelos TL, Cançado LG, Jorio A. Nano-optical Imaging of In-Plane Homojunctions in Graphene and MoS 2 van der Waals Heterostructures on Talc and SiO 2. J Phys Chem Lett 2021; 12:7625-7631. [PMID: 34351150 DOI: 10.1021/acs.jpclett.1c01804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding the impact of doping variations on the physical properties of two-dimensional materials is important for their application in electronic and optoelectronic devices. Here we report a nano-optical study on graphene and MoS2 homojunctions by placing these two materials partly on top of a layered talc substrate, partly on top of an SiO2 substrate. By analyzing the nano-Raman scattering from graphene and the nanophotoluminescense emission from MoS2, two different doping zones are evident with sub-100 nm wide charge oscillations. The oscillations occur abruptly at the homojuction and extend over longer distances away from the interface, indicating imperfect deposition of the two-dimensional layer on the substrate. These results evidence fine and unexpected details of the homojuctions, important to build better electronic and optoelectronic devices.
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Affiliation(s)
- Andreij C Gadelha
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
- Department of Physics, Department of Chemistry, and JILA, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Thiago L Vasconcelos
- Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Duque de Caxias, RJ 25250-020, Brazil
| | - Luiz G Cançado
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Ado Jorio
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
- Electrical Engineering Graduate Program, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
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10
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Pandey SD, Mendonça FG, Rodrigues MN, Faria BPZ, Campos JLE, Noronha IFPC, Vieira SS, Santos NAV, Fernandes LA, Sampaio RA, Colen F, Magriotis ZM, Jorio A. Structural and elemental analysis of biochars in the search of a synthetic path to mimetize anthropic Amazon soils. J Environ Manage 2021; 279:111685. [PMID: 33321351 DOI: 10.1016/j.jenvman.2020.111685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/21/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
In this work, chemical and structural properties of various biochars were analyzed and compared with those from a highly stable anthropic soil, Terra Preta de Índio (TPI). TPI is believed to be responsible for the fertility of Amazonian soils and their stability; therefore, the production of a synthetic TPI would be of great interest for agricultural applications. Biochar produced from different raw biomasses were comprehensively characterized and, based on the obtained results, a preliminary study was performed testing three different routes of chemical activation using nitric acid, phosphoric acid, and potassium hydroxide as activating agents. After chemical activations, metal contents in the biochars decreased, as expected, and high degrees of carbonization were observed. In the case of the activation performed with HNO3, intense signals related to carboxylic groups in TG-MS analysis and in potentiometric titrations point out to a highly oxygenated biochar. Structural analysis showed that activations generated point defects in sp2-carbon structures of biochar, with the material obtained after KOH activation showing a high surface area (569 m2 g-1), an important feature for the use as soil amendment.
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Affiliation(s)
- Sugandha D Pandey
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil; Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil; Departamento de Engenharia, DESA, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil.
| | - Fernanda G Mendonça
- Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil.
| | - Marcio N Rodrigues
- Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais, Av. Universitária, 1000, 39404-547, Montes Claros, MG, Brazil
| | - Beatriz P Z Faria
- Departamento de Engenharia, DESA, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil
| | - João L E Campos
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil
| | - Igor F P C Noronha
- Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil
| | - Sara S Vieira
- Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil
| | - Nadiene A V Santos
- Departamento de Química, Instituto de Ciências Naturais, Universidade Federal de Lavras, Av. Doutor Sylvio Menicucci, 1001 - Kennedy, 37200-900, Lavras, MG, Brazil
| | - Luiz A Fernandes
- Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais, Av. Universitária, 1000, 39404-547, Montes Claros, MG, Brazil
| | - Regynaldo A Sampaio
- Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais, Av. Universitária, 1000, 39404-547, Montes Claros, MG, Brazil
| | - Fernando Colen
- Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais, Av. Universitária, 1000, 39404-547, Montes Claros, MG, Brazil
| | - Zuy M Magriotis
- Departamento de Engenharia, Escola de Engenharia, Universidade Federal de Lavras, Av. Doutor Sylvio Menicucci, 1001 - Kennedy, 37200-900, Lavras, MG, Brazil
| | - Ado Jorio
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31.270-901, Belo Horizonte, MG, Brazil.
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11
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Cunha R, Lafeta L, Fonseca EA, Barbosa A, Romano-Silva MA, Vieira R, Jorio A, Malard LM. Nonlinear and vibrational microscopy for label-free characterization of amyloid-β plaques in Alzheimer's disease model. Analyst 2021; 146:2945-2954. [DOI: 10.1039/d1an00074h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Multimodal optical imaging was used for characterization of amyloid-β plaques in mouse brain tissues. We obtained high-resolution images for different biomarkers and investigated vibrational fingerprints that could be used for diagnostic purposes.
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Affiliation(s)
- Renan Cunha
- Departamento de Física
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Lucas Lafeta
- Departamento de Física
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Emerson A. Fonseca
- Departamento de Física
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Alexandre Barbosa
- Departamento de Física
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Marco A. Romano-Silva
- Departamento de Saúde Mental
- Faculdade de Medicina
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Rafael Vieira
- Departamento de Bioquímica e Imunologia
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Ado Jorio
- Departamento de Física
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Leandro M. Malard
- Departamento de Física
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
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Araujo FDV, Oliveira VV, Gadelha AC, Carvalho TCV, Fernandes TFD, Silva FWN, Longuinhos R, Ribeiro-Soares J, Jorio A, Souza Filho AG, Alencar RS, Viana BC. Temperature-dependent phonon dynamics and anharmonicity of suspended and supported few-layer gallium sulfide. Nanotechnology 2020; 31:495702. [PMID: 32990274 DOI: 10.1088/1361-6528/abb107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phonons play a fundamental role in the electronic and thermal transport of 2D materials which is crucial for device applications. In this work, we investigate the temperature-dependence of A[Formula: see text] and A[Formula: see text] Raman modes of suspended and supported mechanically exfoliated few-layer gallium sulfide (GaS), accessing their relevant thermodynamic Grüneisen parameters and anharmonicity. The Raman frequencies of these two phonons soften with increasing temperature with different [Formula: see text] temperature coefficients. The first-order temperature coefficients θ of A[Formula: see text] mode is ∼ -0.016 cm-1/K, independent of the number of layers and the support. In contrast, the θ of A[Formula: see text] mode is smaller for two-layer GaS and constant for thicker samples (∼ -0.006 2 cm-1 K-1). Furthermore, for two-layer GaS, the θ value is ∼ -0.004 4 cm-1 K-1 for the supported sample, while it is even smaller for the suspended one (∼ -0.002 9 cm-1 K-1). The higher θ value for supported and thicker samples was attributed to the increase in phonon anharmonicity induced by the substrate surface roughness and Umklapp phonon scattering. Our results shed new light on the influence of the substrate and number of layers on the thermal properties of few-layer GaS, which are fundamental for developing atomically-thin GaS electronic devices.
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Affiliation(s)
- Francisco D V Araujo
- Pós-Graduação em Ciência e Engenharia dos Materiais, Universidade Federal do Piauí, Teresina, Piauí, 64049-550, Brazil
- Instituto Federal de Educação, Ciência e Tecnologia do Piauí-IFPI, 64760-000, Piauí, Brazil
| | - Victor V Oliveira
- Faculdade de Física, Universidade Federal do Pará, Belém, Pará, 66075-110 Brazil
| | - Andreij C Gadelha
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 30270-901 Brazil
| | - Thais C V Carvalho
- Departamento de Física, Universidade Federal do Piauí, Teresina, Piauí, 64049-550, Brazil
| | - Thales F D Fernandes
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 30270-901 Brazil
| | - Francisco W N Silva
- Instituto Federal de Educação, Ciência e Tecnologia do Maranhão-Campus Alcântara, Alcântara, Maranhão, Brazil
| | - R Longuinhos
- Departamento de Física, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-000, Brazil
| | - Jenaina Ribeiro-Soares
- Departamento de Física, Universidade Federal de Lavras, Lavras, Minas Gerais, 37200-000, Brazil
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 30270-901 Brazil
| | - Antonio G Souza Filho
- Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, Ceará, 60455-900, Brazil
| | - Rafael S Alencar
- Faculdade de Física, Universidade Federal do Pará, Belém, Pará, 66075-110 Brazil
| | - Bartolomeu C Viana
- Pós-Graduação em Ciência e Engenharia dos Materiais, Universidade Federal do Piauí, Teresina, Piauí, 64049-550, Brazil
- Departamento de Física, Universidade Federal do Piauí, Teresina, Piauí, 64049-550, Brazil
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13
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Oliveira BS, Archanjo BS, Valaski R, Achete CA, Cançado LG, Jorio A, Vasconcelos TL. Nanofabrication of plasmon-tunable nanoantennas for tip-enhanced Raman spectroscopy. J Chem Phys 2020; 153:114201. [DOI: 10.1063/5.0021560] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Bruno S. Oliveira
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Duque de Caxias, RJ 25250-020, Brazil
| | - Bráulio S. Archanjo
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Duque de Caxias, RJ 25250-020, Brazil
| | - Rogério Valaski
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Duque de Caxias, RJ 25250-020, Brazil
| | - Carlos A. Achete
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Duque de Caxias, RJ 25250-020, Brazil
| | - Luiz Gustavo Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30270-901, Brazil
| | - Ado Jorio
- Electrical Engineering and Innovation Technology Graduate Programs, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30270-901, Brazil
| | - Thiago L. Vasconcelos
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Duque de Caxias, RJ 25250-020, Brazil
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Fonseca EA, Lafetá L, Cunha R, Miranda H, Campos J, Medeiros HG, Romano-Silva MA, Silva RA, Barbosa AS, Vieira RP, Malard LM, Jorio A. A fingerprint of amyloid plaques in a bitransgenic animal model of Alzheimer's disease obtained by statistical unmixing analysis of hyperspectral Raman data. Analyst 2020; 144:7049-7056. [PMID: 31657367 DOI: 10.1039/c9an01631g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The global prevalence of Alzheimer's disease (AD) points to endemic levels, especially considering the increase of average life expectancy worldwide. AD diagnosis based on early biomarkers and better knowledge of related pathophysiology are both crucial in the search for medical interventions that are able to modify AD progression. In this study we used unsupervised spectral unmixing statistical techniques to identify the vibrational spectral signature of amyloid β aggregation in neural tissues, as early biomarkers of AD in an animal model. We analyzed spectral images composed of a total of 55 051 Raman spectra obtained from the frontal cortex and hippocampus of five bitransgenic APPswePS1ΔE9 mice, and colocalized amyloid β plaques by other fluorescence techniques. The Raman signatures provided a multifrequency fingerprint consistent with the results of synthesized amyloid β fibrils. The fingerprint obtained from unmixed analysis in neural tissues is shown to provide a detailed image of amyloid plaques in the brain, with the potential to be used as biomarkers for non-invasive early diagnosis and pathophysiology studies in AD on the retina.
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Affiliation(s)
- Emerson A Fonseca
- Departamento de Física, ICEx, UFMG, Belo Horizonte, MG 31270-901, Brazil.
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Nakar D, Gordeev G, Machado LD, Popovitz-Biro R, Rechav K, Oliveira EF, Kusch P, Jorio A, Galvão DS, Reich S, Joselevich E. Few-Wall Carbon Nanotube Coils. Nano Lett 2020; 20:953-962. [PMID: 31869233 DOI: 10.1021/acs.nanolett.9b03977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
While various electronic components based on carbon nanotubes (CNTs) have already been demonstrated, the realization of miniature electromagnetic coils based on CNTs remains a challenge. Coils made of single-wall CNTs with accessible ends for contacting have been recently demonstrated but were found unsuitable to act as electromagnetic coils because of electrical shorting between their turns. Coils made of a few-wall CNT could in principle allow an insulated flow of current and thus be potential candidates for realizing CNT-based electromagnetic coils. However, no such CNT structure has been produced so far. Here, we demonstrate the formation of few-wall CNT coils and characterize their structural, optical, vibrational, and electrical properties using experimental and computational tools. The coils are made of CNTs with 2, 3, or 4 walls. They have accessible ends for electrical contacts and low defect densities. The coil diameters are on the order of one micron, like those of single-wall CNT coils, despite the higher rigidity of few-wall CNTs. Coils with as many as 163 turns were found, with their turns organized in a rippled raft configuration. These coils are promising candidates for a variety of miniature devices based on electromagnetic coils, such as electromagnets, inductors, transformers, and motors. Being chirally and enantiomerically pure few-wall CNT bundles, they are also ideal for fundamental studies of interwall coupling and superconductivity in CNTs.
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Affiliation(s)
- Dekel Nakar
- Department of Materials and Interfaces , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Georgy Gordeev
- Department of Physics , Freie Universität Berlin , 14195 Berlin , Germany
| | - Leonardo D Machado
- Department of Theoretical and Experimental Physics , Federal University of Rio Grande do Norte , Natal , Rio Grande do Norte 59078-970 , Brazil
| | - Ronit Popovitz-Biro
- Department of Chemical Research Support , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Katya Rechav
- Department of Chemical Research Support , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Eliezer F Oliveira
- Applied Physics Department , State University of Campinas - UNICAMP , Campinas , São Paulo 13083-859 , Brazil
- Center for Computational Engineering and Sciences (CCES) , State University of Campinas - UNICAMP , Campinas , São Paulo 13083-859 , Brazil
| | - Patryk Kusch
- Department of Physics , Freie Universität Berlin , 14195 Berlin , Germany
| | - Ado Jorio
- Departamento de Física , Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais 31270-901 , Brazil
| | - Douglas S Galvão
- Applied Physics Department , State University of Campinas - UNICAMP , Campinas , São Paulo 13083-859 , Brazil
- Center for Computational Engineering and Sciences (CCES) , State University of Campinas - UNICAMP , Campinas , São Paulo 13083-859 , Brazil
| | - Stephanie Reich
- Department of Physics , Freie Universität Berlin , 14195 Berlin , Germany
| | - Ernesto Joselevich
- Department of Materials and Interfaces , Weizmann Institute of Science , Rehovot 7610001 , Israel
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Batista RJC, Dias RF, Barboza APM, de Oliveira AB, Manhabosco TM, Gomes-Silva TR, Matos MJS, Gadelha AC, Rabelo C, Cançado LGL, Jorio A, Chacham H, Neves BRA. Nanomechanics of few-layer materials: do individual layers slide upon folding? Beilstein J Nanotechnol 2020; 11:1801-1808. [PMID: 33335824 PMCID: PMC7722626 DOI: 10.3762/bjnano.11.162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/16/2020] [Indexed: 05/17/2023]
Abstract
Folds naturally appear on nanometrically thin materials, also called "2D materials", after exfoliation, eventually creating folded edges across the resulting flakes. We investigate the adhesion and flexural properties of single-layered and multilayered 2D materials upon folding in the present work. This is accomplished by measuring and modeling mechanical properties of folded edges, which allows for the experimental determination of the bending stiffness (κ) of multilayered 2D materials as a function of the number of layers (n). In the case of talc, we obtain κ ∝ n 3 for n ≥ 5, indicating no interlayer sliding upon folding, at least in this thickness range. In contrast, tip-enhanced Raman spectroscopy measurements on edges in folded graphene flakes, 14 layers thick, show no significant strain. This indicates that layers in graphene flakes, up to 5 nm thick, can still slip to relieve stress, showing the richness of the effect in 2D systems. The obtained interlayer adhesion energy for graphene (0.25 N/m) and talc (0.62 N/m) is in good agreement with recent experimental results and theoretical predictions. The obtained value for the adhesion energy of graphene on a silicon substrate is also in agreement with previous results.
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Affiliation(s)
- Ronaldo J C Batista
- Departamento de Física, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil
| | - Rafael F Dias
- Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil
| | - Ana P M Barboza
- Departamento de Física, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil
| | - Alan B de Oliveira
- Departamento de Física, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil
| | - Taise M Manhabosco
- Departamento de Física, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil
| | - Thiago R Gomes-Silva
- Departamento de Física, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil
| | - Matheus J S Matos
- Departamento de Física, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil
| | - Andreij C Gadelha
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
| | - Cassiano Rabelo
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
| | - Luiz G L Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
| | - Hélio Chacham
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
| | - Bernardo R A Neves
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
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Alencar RS, Rabelo C, Miranda HLS, Vasconcelos TL, Oliveira BS, Ribeiro A, Públio BC, Ribeiro-Soares J, Filho AGS, Cançado LG, Jorio A. Probing Spatial Phonon Correlation Length in Post-Transition Metal Monochalcogenide GaS Using Tip-Enhanced Raman Spectroscopy. Nano Lett 2019; 19:7357-7364. [PMID: 31469281 DOI: 10.1021/acs.nanolett.9b02974] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The knowledge of the phonon coherence length is of great importance for two-dimensional-based materials since phonons can limit the lifetime of charge carriers and heat dissipation. Here we use tip-enhanced Raman spectroscopy (TERS) to measure the spatial correlation length Lc of the A1g1 and A1g2 phonons of monolayer and few-layer gallium sulfide (GaS). The differences in Lc values are responsible for different enhancements of the A1g modes, with A1g1 always enhancing more than the A1g2, independently of the number of GaS layers. For five layers, the results show an Lc of 64 and 47 nm for A1g1 and A1g2, respectively, and the coherence lengths decrease when decreasing the number of layers, indicating that scattering with the surface roughness plays an important role.
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Affiliation(s)
- R S Alencar
- Faculdade de Física , Universidade Federal do Pará , 66075-110 Belém-PA , Brazil
- Departamento de Física , Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais 30270-901 , Brazil
- Departamento de Física , Centro de Ciências, Universidade Federal do Ceará , P. O. Box 6030, Fortaleza , Ceará 60455-900 , Brazil
| | - Cassiano Rabelo
- Programa de Pós-Graduação em Engenharia Elétrica , Universidade Federal de Minas Gerais , Av. Antônio Carlos 6627 , 31270-901 Belo Horizonte , MG , Brazil
| | - Hudson L S Miranda
- Programa de Pós-Graduação em Engenharia Elétrica , Universidade Federal de Minas Gerais , Av. Antônio Carlos 6627 , 31270-901 Belo Horizonte , MG , Brazil
| | - Thiago L Vasconcelos
- Divisão de Metrologia de Materiais , Instituto Nacional de Metrologia Qualidade e Tecnologia (INMETRO) , Duque de Caxias, Rio de Janeiro 25250-020 , Brazil
| | - Bruno S Oliveira
- Divisão de Metrologia de Materiais , Instituto Nacional de Metrologia Qualidade e Tecnologia (INMETRO) , Duque de Caxias, Rio de Janeiro 25250-020 , Brazil
| | - Aroldo Ribeiro
- Departamento de Física , Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais 30270-901 , Brazil
| | - Bruno C Públio
- Departamento de Física , Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais 30270-901 , Brazil
| | - Jenaina Ribeiro-Soares
- Departamento de Física , Universidade Federal de Lavras , Lavras , Minas Gerais 37200-000 , Brazil
| | - A G Souza Filho
- Departamento de Física , Centro de Ciências, Universidade Federal do Ceará , P. O. Box 6030, Fortaleza , Ceará 60455-900 , Brazil
| | - Luiz Gustavo Cançado
- Departamento de Física , Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais 30270-901 , Brazil
| | - Ado Jorio
- Departamento de Física , Universidade Federal de Minas Gerais , Belo Horizonte , Minas Gerais 30270-901 , Brazil
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Boukhoubza I, Khenfouch M, Achehboune M, Mothudi BM, Zorkani I, Jorio A. X-ray diffraction investigations of nanostructured ZnO coated with reduced graphene oxide. ACTA ACUST UNITED AC 2019. [DOI: 10.1088/1742-6596/1292/1/012011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Li H, Gordeev G, Wasserroth S, Chakravadhanula VSK, Neelakandhan SKC, Hennrich F, Jorio A, Reich S, Krupke R, Flavel BS. Inner- and outer-wall sorting of double-walled carbon nanotubes. Nat Nanotechnol 2017; 12:1176-1182. [PMID: 28967894 DOI: 10.1038/nnano.2017.207] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/05/2017] [Indexed: 06/07/2023]
Abstract
Double-walled carbon nanotubes (DWCNTs) consist of two coaxially aligned single-walled carbon nanotubes (SWCNTs), and previous sorting methods only achieved outer-wall electronic-type selectivity. Here, a separation technique capable of sorting DWCNTs by semiconducting (S) or metallic (M) inner- and outer-wall electronic type is presented. Electronic coupling between the inner and outer wall is used to alter the surfactant coating around each of the DWCNT types, and aqueous gel permeation is used to separate them. Aqueous methods are used to remove SWCNT species from the raw material and prepare enriched DWCNT fractions. The enriched DWCNT fractions are then transferred into either chlorobenzene or toluene using the copolymer PFO-BPy to yield the four inner@outer combinations of M@M, M@S, S@M and S@S. The high purity of the resulting fractions is verified by absorption measurements, transmission electron microscopy, atomic force microscopy, resonance Raman mapping and high-density field-effect transistor devices.
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Affiliation(s)
- Han Li
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - Georgy Gordeev
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Sören Wasserroth
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Venkata Sai Kiran Chakravadhanula
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
- Helmholtz Institute Ulm Electrochemical Energy Storage, 89081 Ulm, Germany
| | - Shyam Kumar Chethala Neelakandhan
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
- Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Frank Hennrich
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - Ado Jorio
- Department of Physics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Stephanie Reich
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Ralph Krupke
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
- Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Benjamin Scott Flavel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
- Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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20
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Saraiva A, Júnior FSDA, de Melo E Souza R, Pena AP, Monken CH, Santos MF, Koiller B, Jorio A. Photonic Counterparts of Cooper Pairs. Phys Rev Lett 2017; 119:193603. [PMID: 29219533 DOI: 10.1103/physrevlett.119.193603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Indexed: 06/07/2023]
Abstract
The microscopic theory of superconductivity raised the disruptive idea that electrons couple through the elusive exchange of virtual phonons, overcoming the strong Coulomb repulsion to form Cooper pairs. Light is also known to interact with atomic vibrations, as, for example, in the Raman effect. We show that photon pairs exchange virtual vibrations in transparent media, leading to an effective photon-photon interaction identical to that for electrons in the BCS theory of superconductivity, in spite of the fact that photons are bosons. In this scenario, photons may exchange energy without matching a quantum of vibration of the medium. As a result, pair correlations for photons scattered away from the Raman resonances are expected to be enhanced. An experimental demonstration of this effect is provided here by time-correlated Raman measurements in different media. The experimental data confirm our theoretical interpretation of a photonic Cooper pairing, without the need for any fitting parameters.
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Affiliation(s)
- André Saraiva
- Instituto de Física, UFRJ, CP 68528, Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - Filomeno S de Aguiar Júnior
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Reinaldo de Melo E Souza
- Instituto de Física, UFRJ, CP 68528, Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
- Instituto de Física, UFF, Niterói, Rio de Janeiro 24210-346, Brazil
| | - Arthur Patrocínio Pena
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Carlos H Monken
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Marcelo F Santos
- Instituto de Física, UFRJ, CP 68528, Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - Belita Koiller
- Instituto de Física, UFRJ, CP 68528, Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - Ado Jorio
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627, Belo Horizonte, Minas Gerais 31270-901, Brazil
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21
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Lafetá L, Cadore AR, Mendes-de-Sa TG, Watanabe K, Taniguchi T, Campos LC, Jorio A, Malard LM. Anomalous Nonlinear Optical Response of Graphene Near Phonon Resonances. Nano Lett 2017; 17:3447-3451. [PMID: 28541053 DOI: 10.1021/acs.nanolett.7b00329] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work we probe the third-order nonlinear optical property of graphene and hexagonal boron nitride and their heterostructure by the use of coherent anti-Stokes Raman spectroscopy. When the energy difference of the two input fields matches the phonon energy, the anti-Stokes emission intensity is enhanced in h-BN, as usually expected, while for graphene an anomalous decrease is observed. This behavior can be understood in terms of a coupling between the electronic continuum and a discrete phonon state. We have also measured a graphene/h-BN heterostructure and demonstrate that the anomalous effect in graphene dominates the heterostructure nonlinear optical response.
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Affiliation(s)
- Lucas Lafetá
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Alisson R Cadore
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Thiago G Mendes-de-Sa
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Kenji Watanabe
- National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba-city, Ibaraki 305-0047, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba-city, Ibaraki 305-0047, Japan
| | - Leonardo C Campos
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Leandro M Malard
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais 31270-901, Brazil
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22
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Versiani AF, Astigarraga RG, Rocha ESO, Barboza APM, Kroon EG, Rachid MA, Souza DG, Ladeira LO, Barbosa-Stancioli EF, Jorio A, Da Fonseca FG. Multi-walled carbon nanotubes functionalized with recombinant Dengue virus 3 envelope proteins induce significant and specific immune responses in mice. J Nanobiotechnology 2017; 15:26. [PMID: 28376812 PMCID: PMC5379608 DOI: 10.1186/s12951-017-0259-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/20/2017] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Dengue is the most prevalent arthropod-borne viral disease in the world. In this article we present results on the development, characterization and immunogenic evaluation of an alternative vaccine candidate against Dengue. METHODS The MWNT-DENV3E nanoconjugate was developed by covalent functionalization of carboxylated multi-walled carbon nanotubes (MWNT) with recombinant dengue envelope (DENV3E) proteins. The recombinant antigens were bound to the MWNT using a diimide-activated amidation process and the immunogen was characterized by TEM, AFM and Raman Spectroscopy. Furthermore, the immunogenicity of this vaccine candidate was evaluated in a murine model. RESULTS Immunization with MWNT-DENV3E induced comparable IgG responses in relation to the immunization with non-conjugated proteins; however, the inoculation of the nanoconjugate into mice generated higher titers of neutralizing antibodies. Cell-mediated responses were also evaluated, and higher dengue-specific splenocyte proliferation was observed in cell cultures derived from mice immunized with MWNT-DENV3E when compared to animals immunized with the non-conjugated DENV3E. CONCLUSIONS Despite the recent licensure of the CYD-TDV dengue vaccine in some countries, results from the vaccine's phase III trial have cast doubts about its overall efficacy and global applicability. While questions about the effectiveness of the CYD-TDV vaccine still lingers, it is wise to keep at hand an array of vaccine candidates, including alternative non-classical approaches like the one presented here.
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MESH Headings
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Viral/blood
- Antibody Formation
- Antigens, Viral/immunology
- Cell Proliferation
- Cytokines/immunology
- Dengue/immunology
- Dengue/prevention & control
- Dengue Vaccines/immunology
- Dengue Vaccines/therapeutic use
- Dengue Virus/immunology
- Female
- Immunity, Cellular
- Immunoglobulin G/blood
- Mice
- Mice, Inbred BALB C
- Microscopy, Atomic Force
- Microscopy, Electron, Transmission
- Nanoconjugates/chemistry
- Nanomedicine
- Nanotubes, Carbon/chemistry
- Recombinant Proteins/chemistry
- Recombinant Proteins/immunology
- Spectrum Analysis, Raman
- Spleen/cytology
- Vaccines, Subunit/immunology
- Vaccines, Subunit/therapeutic use
- Viral Envelope Proteins/immunology
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Affiliation(s)
- Alice F. Versiani
- Laboratory of Basic and Applied Virology, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Ruiz G. Astigarraga
- Laboratory of Basic and Applied Virology, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Eliseu S. O. Rocha
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Ana Paula M. Barboza
- Laboratório de Nanoscopia, Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Erna G. Kroon
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Milene A. Rachid
- Departamento de Patologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Daniele G. Souza
- Laboratory of Microorganism-Host Interaction, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Luiz O. Ladeira
- Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Edel F. Barbosa-Stancioli
- Laboratory of Basic and Applied Virology, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Ado Jorio
- Laboratório de Nanoscopia, Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Flávio G. Da Fonseca
- Laboratory of Basic and Applied Virology, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
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23
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Kasperczyk M, de Aguiar Júnior FS, Rabelo C, Saraiva A, Santos MF, Novotny L, Jorio A. Temporal Quantum Correlations in Inelastic Light Scattering from Water. Phys Rev Lett 2016; 117:243603. [PMID: 28009217 DOI: 10.1103/physrevlett.117.243603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Indexed: 06/06/2023]
Abstract
Water is one of the most prevalent chemicals on our planet, an integral part of both our environment and our existence as a species. Yet it is also rich in anomalous behaviors. Here we reveal that water is a novel-yet ubiquitous-source for quantum correlated photon pairs at ambient conditions. The photon pairs are produced through Raman scattering, and the correlations arise from the shared quantum of a vibrational mode between the Stokes and anti-Stokes scattering events. We confirm the nonclassical nature of the produced photon pairs by showing that the cross-correlation and autocorrelations of the signals violate a Cauchy-Schwarz inequality by over 5 orders of magnitude. The unprecedented degree of violating the inequality in pure water, as well as the well-defined polarization properties of the photon pairs, points to its usefulness in quantum information.
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Affiliation(s)
| | - Filomeno S de Aguiar Júnior
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horiztone, Minas Gerais 31270-901, Brazil
| | - Cassiano Rabelo
- Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horiztone, Minas Gerais 31270-901, Brazil
| | - Andre Saraiva
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - Marcelo F Santos
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - Lukas Novotny
- Photonics Laboratory, ETH Zürich, 8093 Zürich, Switzerland
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horiztone, Minas Gerais 31270-901, Brazil
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24
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Munk M, Ladeira LO, Carvalho BC, Camargo LSA, Raposo NRB, Serapião RV, Quintão CCR, Silva SR, Soares JS, Jorio A, Brandão HM. Efficient delivery of DNA into bovine preimplantation embryos by multiwall carbon nanotubes. Sci Rep 2016; 6:33588. [PMID: 27642034 PMCID: PMC5027538 DOI: 10.1038/srep33588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/24/2016] [Indexed: 12/22/2022] Open
Abstract
The pellucid zone (PZ) is a protective embryonic cells barrier against chemical, physical or biological substances. This put, usual transfection methods are not efficient for mammal oocytes and embryos as they are exclusively for somatic cells. Carbon nanotubes have emerged as a new method for gene delivery, and they can be an alternative for embryos transfection, however its ability to cross the PZ and mediated gene transfer is unknown. Our data confirm that multiwall carbon nanotubes (MWNTs) can cross the PZ and delivery of pDNA into in vitro-fertilized bovine embryos. The degeneration rate and the expression of genes associated to cell viability were not affected in embryos exposed to MWNTs. Those embryos, however, had lower cell number and higher apoptotic cell index, but this did not impair the embryonic development. This study shows the potential utility of the MWNT for the development of new method for delivery of DNA into bovine embryos.
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Affiliation(s)
- Michele Munk
- Department of Biology, Federal University of Juiz de Fora, 36036-900, Juiz de Fora, Brazil
| | - Luiz O Ladeira
- Department of Physics, Federal University of Minas Gerais, 31270-901 Belo Horizonte, Brazil
| | - Bruno C Carvalho
- Brazilian Agricultural Research Corporation, Embrapa Dairy Cattle (CNPGL), 36038-330 Juiz de Fora, Brazil
| | - Luiz S A Camargo
- Brazilian Agricultural Research Corporation, Embrapa Dairy Cattle (CNPGL), 36038-330 Juiz de Fora, Brazil
| | - Nádia R B Raposo
- Department of Biology, Federal University of Juiz de Fora, 36036-900, Juiz de Fora, Brazil.,Center of Research and Innovation in Health Sciences (NUPICS), Federal University of Juiz de Fora, 36036-900 Juiz de Fora, Brazil
| | - Raquel V Serapião
- Brazilian Agricultural Research Corporation, Embrapa Dairy Cattle (CNPGL), 36038-330 Juiz de Fora, Brazil
| | - Carolina C R Quintão
- Brazilian Agricultural Research Corporation, Embrapa Dairy Cattle (CNPGL), 36038-330 Juiz de Fora, Brazil
| | - Saulo R Silva
- Brazilian Agricultural Research Corporation, Embrapa Dairy Cattle (CNPGL), 36038-330 Juiz de Fora, Brazil
| | - Jaqueline S Soares
- Department of Physics, Federal University of Ouro Preto, 35400-000 Ouro Preto, Brazil
| | - Ado Jorio
- Department of Physics, Federal University of Minas Gerais, 31270-901 Belo Horizonte, Brazil
| | - Humberto M Brandão
- Brazilian Agricultural Research Corporation, Embrapa Dairy Cattle (CNPGL), 36038-330 Juiz de Fora, Brazil
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25
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Shadmi N, Kremen A, Frenkel Y, Lapin ZJ, Machado LD, Legoas SB, Bitton O, Rechav K, Popovitz-Biro R, Galvão DS, Jorio A, Novotny L, Kalisky B, Joselevich E. Defect-Free Carbon Nanotube Coils. Nano Lett 2016; 16:2152-2158. [PMID: 26708150 DOI: 10.1021/acs.nanolett.5b03417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Carbon nanotubes are promising building blocks for various nanoelectronic components. A highly desirable geometry for such applications is a coil. However, coiled nanotube structures reported so far were inherently defective or had no free ends accessible for contacting. Here we demonstrate the spontaneous self-coiling of single-wall carbon nanotubes into defect-free coils of up to more than 70 turns with identical diameter and chirality, and free ends. We characterize the structure, formation mechanism, and electrical properties of these coils by different microscopies, molecular dynamics simulations, Raman spectroscopy, and electrical and magnetic measurements. The coils are highly conductive, as expected for defect-free carbon nanotubes, but adjacent nanotube segments in the coil are more highly coupled than in regular bundles of single-wall carbon nanotubes, owing to their perfect crystal momentum matching, which enables tunneling between the turns. Although this behavior does not yet enable the performance of these nanotube coils as inductive devices, it does point a clear path for their realization. Hence, this study represents a major step toward the production of many different nanotube coil devices, including inductors, electromagnets, transformers, and dynamos.
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Affiliation(s)
| | - Anna Kremen
- Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University , Ramat-Gan, 52900, Israel
| | - Yiftach Frenkel
- Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University , Ramat-Gan, 52900, Israel
| | - Zachary J Lapin
- ETH Zürich , Photonics Laboratory, Zürich, 8093, Switzerland
| | - Leonardo D Machado
- Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas , C. P. 6165, 13083-970 Campinas, Sao Paulo, Brazil
| | - Sergio B Legoas
- Departamento de Fisica, CCT, Universidade Federal de Roraima , 69304-000 Boa Vista, Roraima, Brazil
| | | | | | | | - Douglas S Galvão
- Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas , C. P. 6165, 13083-970 Campinas, Sao Paulo, Brazil
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais , Belo Horizonte, MG 31270-901, Brazil
| | - Lukas Novotny
- ETH Zürich , Photonics Laboratory, Zürich, 8093, Switzerland
| | - Beena Kalisky
- Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University , Ramat-Gan, 52900, Israel
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26
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Vasconcelos TL, Archanjo BS, Fragneaud B, Oliveira BS, Riikonen J, Li C, Ribeiro DS, Rabelo C, Rodrigues WN, Jorio A, Achete CA, Cançado LG. Tuning Localized Surface Plasmon Resonance in Scanning Near-Field Optical Microscopy Probes. ACS Nano 2015; 9:6297-6304. [PMID: 26027751 DOI: 10.1021/acsnano.5b01794] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A reproducible route for tuning localized surface plasmon resonance in scattering type near-field optical microscopy probes is presented. The method is based on the production of a focused-ion-beam milled single groove near the apex of electrochemically etched gold tips. Electron energy-loss spectroscopy and scanning transmission electron microscopy are employed to obtain highly spatially and spectroscopically resolved maps of the milled probes, revealing localized surface plasmon resonance at visible and near-infrared wavelengths. By changing the distance L between the groove and the probe apex, the localized surface plasmon resonance energy can be fine-tuned at a desired absorption channel. Tip-enhanced Raman spectroscopy is applied as a test platform, and the results prove the reliability of the method to produce efficient scattering type near-field optical microscopy probes.
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Affiliation(s)
- Thiago L Vasconcelos
- †Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
- ‡Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Duque de Caxias, RJ 25250-020, Brazil
| | - Bráulio S Archanjo
- ‡Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Duque de Caxias, RJ 25250-020, Brazil
| | - Benjamin Fragneaud
- §Departamento de Física, Universidade Federal de Juiz de Fora, Juiz de Fora, MG 36036-900, Brazil
| | - Bruno S Oliveira
- ‡Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Duque de Caxias, RJ 25250-020, Brazil
| | - Juha Riikonen
- ⊥Department of Micro- and Nanosciences, Aalto University, Tietotie 3, 02150 Espoo, Finland
| | - Changfeng Li
- ⊥Department of Micro- and Nanosciences, Aalto University, Tietotie 3, 02150 Espoo, Finland
| | - Douglas S Ribeiro
- †Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
| | - Cassiano Rabelo
- †Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
| | - Wagner N Rodrigues
- †Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
| | - Ado Jorio
- †Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
| | - Carlos A Achete
- ‡Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Duque de Caxias, RJ 25250-020, Brazil
- ∥Departamento de Engenharia Metalúrgica e de Materiais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972, Brazil
| | - Luiz Gustavo Cançado
- †Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
- ‡Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Duque de Caxias, RJ 25250-020, Brazil
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27
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Cano-Marquez AG, Schmidt WG, Ribeiro-Soares J, Gustavo Cançado L, Rodrigues WN, Santos AP, Furtado CA, Autreto PA, Paupitz R, Galvão DS, Jorio A. Enhanced Mechanical Stability of Gold Nanotips through Carbon Nanocone Encapsulation. Sci Rep 2015; 5:10408. [PMID: 26083864 PMCID: PMC4470435 DOI: 10.1038/srep10408] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 04/13/2015] [Indexed: 11/08/2022] Open
Abstract
Gold is a noble metal that, in comparison with silver and copper, has the advantage of corrosion resistance. Despite its high conductivity, chemical stability and biocompatibility, gold exhibits high plasticity, which limits its applications in some nanodevices. Here, we report an experimental and theoretical study on how to attain enhanced mechanical stability of gold nanotips. The gold tips were fabricated by chemical etching and further encapsulated with carbon nanocones via nanomanipulation. Atomic force microscopy experiments were carried out to test their mechanical stability. Molecular dynamics simulations show that the encapsulated nanocone changes the strain release mechanisms at the nanoscale by blocking gold atomic sliding, redistributing the strain along the whole nanostructure. The carbon nanocones are conducting and can induce magnetism, thus opening new avenues on the exploitation of transport, mechanical and magnetic properties of gold covered by sp(2) carbon at the nanoscale.
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Affiliation(s)
- Abraham G. Cano-Marquez
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
- Materials Research Institute, N-261 Millennium Science Complex, Penn State University, University Park, PA 16802, USA
| | - Wesller G. Schmidt
- Centro de Microscopia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30123-970, Brazil
| | - Jenaina Ribeiro-Soares
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Luiz Gustavo Cançado
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Wagner N. Rodrigues
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Adelina P. Santos
- Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, MG, 31270-010, Brazil
| | - Clascidia A. Furtado
- Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, MG, 31270-010, Brazil
| | - Pedro A.S. Autreto
- Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil
| | - Ricardo Paupitz
- Departamento de Física, IGCE, Universidade Estadual Paulista - UNESP, Rio Claro, SP, 13506-900, Brazil
| | - Douglas S. Galvão
- Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil
| | - Ado Jorio
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
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28
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Abstract
We investigate the arrival statistics of Stokes (S) and anti-Stokes (aS) Raman photons generated in thin diamond crystals. Strong quantum correlations between the S and aS signals are observed, which implies that the two processes share the same phonon; that is, the phonon excited in the S process is consumed in the aS process. We show that the intensity cross-correlation g(S,aS)(2)(0), which describes the simultaneous detection of Stokes and anti-Stokes photons, increases steadily with decreasing laser power and saturates at very low pump powers, implying that the number of Stokes-induced aS photons is comparable to the number of spontaneously generated aS photons. Furthermore, the coincidence rate shows a quadratic plus cubic power dependence, indicating the generation of multiple S photons per pulse at high powers.
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29
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Abstract
We demonstrate local strain measurements in graphene by using tip-enhanced Raman spectroscopy (TERS). We find that a single 5 nm particle can induce a radial strain over a lateral distance of ∼170 nm. By treating the particle as a point force on a circular membrane, we find that the strain in the radial direction (r) is ∝ r−(2 3),in agreement with force-displacement measurements conducted on suspended graphene flakes. Our results demonstrate that TERS can be used to map out static strain fields at the nanoscale, which are inaccessible using force-displacement techniques.
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Affiliation(s)
- Ryan Beams
- Institute of Optics, University of Rochester, Rochester, NY 14627, USA
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30
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Archanjo BS, Baptista DL, Sena LA, Cançado LG, Falcão NPS, Jorio A, Achete CA. Nanoscale mapping of carbon oxidation in pyrogenic black carbon from ancient Amazonian anthrosols. Environ Sci Process Impacts 2015; 17:775-779. [PMID: 25699655 DOI: 10.1039/c4em00590b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Understanding soil organic matter is necessary for the development of soil amendments, which are important for sustaining agriculture in humid tropical climates. Ancient Amazonian anthrosols are uniquely high in black recalcitrant carbon, making them extremely fertile. In this study, we use high-resolution electron microscopy and spectroscopy to resolve the oxidation process of carbon in the nanoscale crystallites within the black carbon grains of this special soil. Most alkali and acid chemical extraction methods are known to cause chemical modifications in soil organic matter and to give poor or no information about the real spatial structure of soil aggregates. However, here we show that carbon-oxygen functional groups such as phenol, carbonyl, and carboxyl dominate over different spatial regions, with areas varying from over tens to hundreds of nm(2). The chemical maps show that in the nanoscale grain, the surface has a tendency to be less aromatic than the grain core, where higher oxidative-degradation levels are indicated by the presence of carbonyl and carboxyl groups. A deep understanding of these structures could allow artificial reproduction of these natural events.
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Affiliation(s)
- B S Archanjo
- Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Senhora das Graças, 50, 25250-020 Duque de Caxias, RJ, Brazil.
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31
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Abstract
Inelastic light scattering in crystals has historically been treated as a spatially incoherent process, giving rise to incoherent optical radiation. Here we demonstrate that Raman scattering can be spatially coherent, in which case it depends on the dimensionality and symmetry of the scatterer. Using near-field spectroscopy, we measure a correlation length of ∼30 nm for the optical phonons in graphene, the results varying with vibrational symmetries and spatial confinement of the phonons.
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Affiliation(s)
- Ryan Beams
- Institute of Optics, University of Rochester, Rochester, New York 14627, USA
| | - Luiz Gustavo Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
| | - Sang-Hyun Oh
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG 30123-970, Brazil
| | - Lukas Novotny
- Photonics Laboratory, ETH Zürich, 8093 Zürich, Switzerland*
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32
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Jorio A, Kasperczyk M, Clark N, Neu E, Maletinsky P, Vijayaraghavan A, Novotny L. Optical-phonon resonances with saddle-point excitons in twisted-bilayer graphene. Nano Lett 2014; 14:5687-92. [PMID: 25198466 DOI: 10.1021/nl502412g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Twisted-bilayer graphene (tBLG) exhibits van Hove singularities in the density of states that can be tuned by changing the twisting angle θ. A θ-defined tBLG has been produced and characterized with optical reflectivity and resonance Raman scattering. The θ-engineered optical response is shown to be consistent with persistent saddle-point excitons. Separate resonances with Stokes and anti-Stokes Raman scattering components can be achieved due to the sharpness of the two-dimensional saddle-point excitons, similar to what has been previously observed for one-dimensional carbon nanotubes. The excitation power dependence for the Stokes and anti-Stokes emissions indicate that the two processes are correlated and that they share the same phonon.
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Affiliation(s)
- Ado Jorio
- Photonics Laboratory, ETH Zürich , 8093 Zürich, Switzerland
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33
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Archanjo BS, Araujo JR, Silva AM, Capaz RB, Falcão NPS, Jorio A, Achete CA. Chemical analysis and molecular models for calcium-oxygen-carbon interactions in black carbon found in fertile Amazonian anthrosoils. Environ Sci Technol 2014; 48:7445-7452. [PMID: 24892495 DOI: 10.1021/es501046b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Carbon particles containing mineral matter promote soil fertility, helping it to overcome the rather unfavorable climate conditions of the humid tropics. Intriguing examples are the Amazonian Dark Earths, anthropogenic soils also known as "Terra Preta de Índio'' (TPI), in which chemical recalcitrance and stable carbon with millenary mean residence times have been observed. Recently, the presence of calcium and oxygen within TPI-carbon nanoparticles at the nano- and mesoscale ranges has been demonstrated. In this work, we combine density functional theory calculations, scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transformed infrared spectroscopy, and high resolution X-ray photoelectron spectroscopy of TPI-carbons to elucidate the chemical arrangements of calcium-oxygen-carbon groups at the molecular level in TPI. The molecular models are based on graphene oxide nanostructures in which calcium cations are strongly adsorbed at the oxide sites. The application of material science techniques to the field of soil science facilitates a new level of understanding, providing insights into the structure and functionality of recalcitrant carbon in soil and its implications for food production and climate change.
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Affiliation(s)
- Braulio S Archanjo
- Instituto Nacional de Metrologia, Qualidade e Tecnologia , Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, Rio de Janeiro, Brazil
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Barros AGDA, Bridi JC, de Souza BR, de Castro Júnior C, de Lima Torres KC, Malard L, Jorio A, de Miranda DM, Ashrafi K, Romano-Silva MA. Dopamine signaling regulates fat content through β-oxidation in Caenorhabditis elegans. PLoS One 2014; 9:e85874. [PMID: 24465759 PMCID: PMC3899111 DOI: 10.1371/journal.pone.0085874] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 12/06/2013] [Indexed: 11/26/2022] Open
Abstract
The regulation of energy balance involves an intricate interplay between neural mechanisms that respond to internal and external cues of energy demand and food availability. Compelling data have implicated the neurotransmitter dopamine as an important part of body weight regulation. However, the precise mechanisms through which dopamine regulates energy homeostasis remain poorly understood. Here, we investigate mechanisms through which dopamine modulates energy storage. We showed that dopamine signaling regulates fat reservoirs in Caenorhabditis elegans. We found that the fat reducing effects of dopamine were dependent on dopaminergic receptors and a set of fat oxidation enzymes. Our findings reveal an ancient role for dopaminergic regulation of fat and suggest that dopamine signaling elicits this outcome through cascades that ultimately mobilize peripheral fat depots.
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Affiliation(s)
- Alexandre Guimarães de Almeida Barros
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Jessika Cristina Bridi
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Bruno Rezende de Souza
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Célio de Castro Júnior
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Karen Cecília de Lima Torres
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Leandro Malard
- Departamento de Física, Instituto de Ciências Exatas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ado Jorio
- Departamento de Física, Instituto de Ciências Exatas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Débora Marques de Miranda
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Kaveh Ashrafi
- Department of Physiology, University of California San Francisco, San Francisco, California, United States
| | - Marco Aurélio Romano-Silva
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Machado LD, Legoas SB, Soares JS, Shadmi N, Jorio A, Joselevich E, Galvão DS. Dynamics of the formation of carbon nanotube serpentines. Phys Rev Lett 2013; 110:105502. [PMID: 23521270 DOI: 10.1103/physrevlett.110.105502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Indexed: 06/01/2023]
Abstract
Recently, Geblinger et al. [Nat. Nanotechnol. 3, 195 (2008)] reported the experimental realization of carbon nanotube S-like shaped nanostructures, the so-called carbon nanotube serpentines. We report here results from multimillion fully atomistic molecular dynamics simulations of their formation. We consider one-μm-long carbon nanotubes placed on stepped substrates with and without a catalyst nanoparticle on the top free end of the tube. A force is applied to the upper part of the tube during a short period of time and turned off; then the system is set free to evolve in time. Our results show that these conditions are sufficient to form robust serpentines and validates the general features of the "falling spaghetti model" proposed to explain their formation.
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Affiliation(s)
- L D Machado
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, CP 6165, 13083-970 Campinas, Sao Paulo, Brazil
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Abstract
Raman spectroscopy is a powerful tool to characterize the different types of sp2 carbon nanostructures, including two-dimensional graphene, one-dimensional nanotubes, and the effect of disorder in their structures. This work discusses why sp2 nanocarbons can be considered as prototype materials for the development of nanoscience and nanometrology. The sp2 nanocarbon structures are quickly introduced, followed by a discussion on how this field evolved in the past decades. In sequence, their rather rich Raman spectra composed of many peaks induced by single- and multiple-resonance effects are introduced. The properties of the main Raman peaks are then described, including their dependence on both materials structure and external factors, like temperature, pressure, doping, and environmental effects. Recent applications that are pushing the technique limits, such as multitechnique approach and in situ nanomanipulation, are highlighted, ending with some challenges for new developments in this field.
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Affiliation(s)
- Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil
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37
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Araujo PT, Barbosa Neto NM, Chacham H, Carara SS, Soares JS, Souza AD, Cançado LG, de Oliveira AB, Batista RJC, Joselevich E, Dresselhaus MS, Jorio A. In situ atomic force microscopy tip-induced deformations and Raman spectroscopy characterization of single-wall carbon nanotubes. Nano Lett 2012; 12:4110-4116. [PMID: 22731916 DOI: 10.1021/nl3016347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this work, an atomic force microscope (AFM) is combined with a confocal Raman spectroscopy setup to follow in situ the evolution of the G-band feature of isolated single-wall carbon nanotubes (SWNTs) under transverse deformation. The SWNTs are pressed by a gold AFM tip against the substrate where they are sitting. From eight deformed SWNTs, five exhibit an overall decrease in the Raman signal intensity, while three exhibit vibrational changes related to the circumferential symmetry breaking. Our results reveal chirality dependent effects, which are averaged out in SWNT bundle measurements, including a previously elusive mode symmetry breaking that is here explored using molecular dynamics calculations.
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Affiliation(s)
- P T Araujo
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30123-970 Brazil
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38
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Archanjo BS, Barboza APM, Neves BRA, Malard LM, Ferreira EHM, Brant JC, Alves ES, Plentz F, Carozo V, Fragneaud B, Maciel IO, Almeida CM, Jorio A, Achete CA. The use of a Ga+ focused ion beam to modify graphene for device applications. Nanotechnology 2012; 23:255305. [PMID: 22652838 DOI: 10.1088/0957-4484/23/25/255305] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this work, we clarify the features of the lateral damage of line defects in single layer graphene. The line defects were produced through well-controlled etching of graphene using a Ga(+) focused ion beam. The lateral damage length was obtained from both the integrated intensity of the disorder induced Raman D band and the minimum ion fluence. Also, the line defects were characterized by polarized Raman spectroscopy. It was found that graphene is resilient under the etching conditions since the intensity of the defect induced Raman D peak exhibits a dependence on the direction of the lines relative to the crystalline lattice and also on the direction of the laser polarization relative to the lines. In addition, electrical measurements of the modified graphene were performed. Different ion fluences were used in order to obtain a completely insulating defect line in graphene, which was determined experimentally by means of charge injection and electric force microscopy measurements. These studies demonstrate that a Ga+ ion column combined with Raman spectroscopy is a powerful technique to produce and understand well-defined periodic arrays of defects in graphene, opening possibilities for better control of nanocarbon devices.
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Affiliation(s)
- B S Archanjo
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalização e Qualidade Industrial, Duque de Caxias, RJ, Brazil.
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39
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Jorio A, Cançado LG. Perspectives on Raman spectroscopy of graphene-based systems: from the perfect two-dimensional surface to charcoal. Phys Chem Chem Phys 2012; 14:15246-56. [DOI: 10.1039/c2cp42621h] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Castilho-Almeida EW, Santos HFD, Miranda AMD, Jorio A, Ferreira EHM, Achete CA, Armond RASZ, Anconi CPA, Almeida WBD. Estudo teórico e experimental de espectros infravermelho de ésteres de ácido graxo presentes na composição do biodiesel de soja. QUIM NOVA 2012. [DOI: 10.1590/s0100-40422012000900009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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41
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Abstract
When two identical two-dimensional periodic structures are superposed, a mismatch rotation angle between the structures generates a superlattice. This effect is commonly observed in graphite, where the rotation between graphene layers generates Moiré patterns in scanning tunneling microscopy images. Here, a study of intravalley and intervalley double-resonance Raman processes mediated by static potentials in rotationally stacked bilayer graphene is presented. The peak properties depend on the mismatch rotation angle and can be used as an optical signature for superlattices in bilayer graphene. An atomic force microscopy system is used to produce and identify specific rotationally stacked bilayer graphenes that demonstrate the validity of our model.
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Affiliation(s)
- Victor Carozo
- Departamento de Engenharia Metalúrgica e de Materiais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972, Brazil
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Cançado LG, Jorio A, Ferreira EHM, Stavale F, Achete CA, Capaz RB, Moutinho MVO, Lombardo A, Kulmala TS, Ferrari AC. Quantifying defects in graphene via Raman spectroscopy at different excitation energies. Nano Lett 2011; 11:3190-6. [PMID: 21696186 DOI: 10.1021/nl201432g] [Citation(s) in RCA: 1108] [Impact Index Per Article: 85.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a Raman study of Ar(+)-bombarded graphene samples with increasing ion doses. This allows us to have a controlled, increasing, amount of defects. We find that the ratio between the D and G peak intensities, for a given defect density, strongly depends on the laser excitation energy. We quantify this effect and present a simple equation for the determination of the point defect density in graphene via Raman spectroscopy for any visible excitation energy. We note that, for all excitations, the D to G intensity ratio reaches a maximum for an interdefect distance ∼3 nm. Thus, a given ratio could correspond to two different defect densities, above or below the maximum. The analysis of the G peak width and its dispersion with excitation energy solves this ambiguity.
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Affiliation(s)
- L G Cançado
- Departamento de Física, Universidade Federal de Minas Gerais, 30123-970, Belo Horizonte, Brazil.
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43
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Archanjo B, Maciel I, Martins Ferreira E, Peripolli S, Damasceno J, Achete C, Jorio A. Ion beam nanopatterning and micro-Raman spectroscopy analysis on HOPG for testing FIB performances. Ultramicroscopy 2011; 111:1338-42. [DOI: 10.1016/j.ultramic.2011.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 04/06/2011] [Accepted: 04/24/2011] [Indexed: 10/18/2022]
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44
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Dresselhaus MS, Jorio A, Cançado LG, Dresselhaus G, Saito R. Raman Spectroscopy: Characterization of Edges, Defects, and the Fermi Energy of Graphene and sp 2 Carbons. Graphene Nanoelectronics 2011. [DOI: 10.1007/978-3-642-22984-8_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Dresselhaus MS, Jorio A, Souza Filho AG, Saito R. Defect characterization in graphene and carbon nanotubes using Raman spectroscopy. Philos Trans A Math Phys Eng Sci 2010; 368:5355-77. [PMID: 21041218 DOI: 10.1098/rsta.2010.0213] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
This review discusses advances that have been made in the study of defect-induced double-resonance processes in nanographite, graphene and carbon nanotubes, mostly coming from combining Raman spectroscopic experiments with microscopy studies and from the development of new theoretical models. The disorder-induced peak frequencies and intensities are discussed, with particular emphasis given to how the disorder-induced features evolve with increasing amounts of disorder. We address here two systems, ion-bombarded graphene and nanographite, where disorder is represented by point defects and boundaries, respectively. Raman spectroscopy is used to study the 'atomic structure' of the defect, making it possible, for example, to distinguish between zigzag and armchair edges, based on selection rules of phonon scattering. Finally, a different concept is discussed, involving the effect that defects have on the lineshape of Raman-allowed peaks, owing to local electron and phonon energy renormalization. Such effects can be observed by near-field optical measurements on the G' feature for doped single-walled carbon nanotubes.
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Affiliation(s)
- M S Dresselhaus
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA.
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46
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Soares JS, Barboza APM, Araujo PT, Barbosa Neto NM, Nakabayashi D, Shadmi N, Yarden TS, Ismach A, Geblinger N, Joselevich E, Vilani C, Cançado LG, Novotny L, Dresselhaus G, Dresselhaus MS, Neves BRA, Mazzoni MSC, Jorio A. Modulating the electronic properties along carbon nanotubes via tube-substrate interaction. Nano Lett 2010; 10:5043-5048. [PMID: 21050011 DOI: 10.1021/nl103245q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We study single wall carbon nanotubes (SWNTs) deposited on quartz. Their Raman spectrum depends on the tube-substrate morphology, and in some cases, it shows that the same SWNT-on-quartz system exhibits a mixture of semiconductor and metal behavior, depending on the orientation between the tube and the substrate. We also address the problem using electric force microscopy and ab initio calculations, both showing that the electronic properties along a single SWNT are being modulated via tube-substrate interaction.
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Affiliation(s)
- Jaqueline S Soares
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
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47
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Ladeira MS, Andrade VA, Gomes ERM, Aguiar CJ, Moraes ER, Soares JS, Silva EE, Lacerda RG, Ladeira LO, Jorio A, Lima P, Leite MF, Resende RR, Guatimosim S. Highly efficient siRNA delivery system into human and murine cells using single-wall carbon nanotubes. Nanotechnology 2010; 21:385101. [PMID: 20798464 DOI: 10.1088/0957-4484/21/38/385101] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Development of RNA interference (RNAi) technology utilizing short interfering RNA sequences (siRNA) has focused on creating methods for delivering siRNAs to cells and for enhancing siRNA stability in vitro and in vivo. Here, we describe a novel approach for siRNA cellular delivery using siRNA coiling into carboxyl-functionalized single-wall carbon nanotubes (SWCNTs). The CNT-siRNA delivery system successfully demonstrates nonspecific toxicity and transfection efficiency greater than 95%. This approach offers the potential for siRNA delivery into different types of cells, including hard-to-transfect cells, such as neuronal cells and cardiomyocytes. We also tested the CNT-siRNA system in a non-metastatic human hepatocellular carcinoma cell line (SKHep1). In all types of cells used in this work the CNT-siRNA delivery system showed high efficiency and apparent no side effects for various in vitro applications.
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Affiliation(s)
- M S Ladeira
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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48
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Jorio A, Lucchese MM, Stavale F, Ferreira EHM, Moutinho MVO, Capaz RB, Achete CA. Raman study of ion-induced defects in N-layer graphene. J Phys Condens Matter 2010; 22:334204. [PMID: 21386494 DOI: 10.1088/0953-8984/22/33/334204] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Raman scattering is used to study the effect of low energy (90 eV) Ar(+) ion bombardment in graphene samples as a function of the number of layers N. The evolution of the intensity ratio between the G band (1585 cm(-1)) and the disorder-induced D band (1345 cm(-1)) with ion fluence is determined for mono-, bi-, tri- and ∼50-layer graphene samples, providing a spectroscopy-based method to study the penetration of these low energy Ar(+) ions in AB Bernal stacked graphite, and how they affect the graphene sheets. The results clearly depend on the number of layers. We also analyze the evolution of the overall integrated Raman intensity and the integrated intensity for disorder-induced versus Raman-allowed peaks.
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Affiliation(s)
- Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30123-970, Brazil.
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49
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Affiliation(s)
- Ado Jorio
- Departamento de Física, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, Brazil 30.123-970.
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50
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Campos-Delgado J, Maciel IO, Cullen DA, Smith DJ, Jorio A, Pimenta MA, Terrones H, Terrones M. Chemical vapor deposition synthesis of N-, P-, and Si-doped single-walled carbon nanotubes. ACS Nano 2010; 4:1696-702. [PMID: 20201558 DOI: 10.1021/nn901599g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Here we report the synthesis of single-walled carbon nanotube bundles by chemical vapor deposition in the presence of electron donor elements (N, P, and Si). In order to introduce each dopant into the graphitic carbon lattice, different precursors containing the doping elements (benzylamine, pyrazine, triphenylphosphine, and methoxytrimethylsilane) were added at various concentrations into ethanol/ferrocene solutions. The synthesized nanotubes and byproduct were characterized by electron microscopy and Raman spectroscopy. Our results reveal intrinsic structural and electronic differences for the N-, P-, and Si- doped nanotubes. These tubes can now be tested for the fabrication of electronic nanodevices, and their performance can be observed.
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Affiliation(s)
- Jessica Campos-Delgado
- Advanced Materials Department, IPICYT, Camino a la Presa San Jose 2055, Col. Lomas 4a Seccion, 78216 San Luis Potosi, SLP, Mexico
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