1
|
Sasso A, Capaccio A, Rusciano G. Exploring Reliable and Efficient Plasmonic Nanopatterning for Surface- and Tip-Enhanced Raman Spectroscopies. Int J Mol Sci 2023; 24:16164. [PMID: 38003354 PMCID: PMC10671507 DOI: 10.3390/ijms242216164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Surface-enhanced Raman scattering (SERS) is of growing interest for a wide range of applications, especially for biomedical analysis, thanks to its sensitivity, specificity, and multiplexing capabilities. A crucial role for successful applications of SERS is played by the development of reproducible, efficient, and facile procedures for the fabrication of metal nanostructures (SERS substrates). Even more challenging is to extend the fabrication techniques of plasmonic nano-textures to atomic force microscope (AFM) probes to carry out tip-enhanced Raman spectroscopy (TERS) experiments, in which spatial resolution below the diffraction limit is added to the peculiarities of SERS. In this short review, we describe recent studies performed by our group during the last ten years in which novel nanofabrication techniques have been successfully applied to SERS and TERS experiments for studying bio-systems and molecular species of environmental interest.
Collapse
Affiliation(s)
- Antonio Sasso
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (A.C.); (G.R.)
| | - Angela Capaccio
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (A.C.); (G.R.)
- Institute of Food Sciences, URT-CNR Department of Biology, University of Naples “Federico II”, 80126 Naples, Italy
| | - Giulia Rusciano
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (A.C.); (G.R.)
| |
Collapse
|
2
|
Wang T, Ye L, Xiao P, Zhu P, Gui X, Zhuang L. Dynamic modulation of a surface-enhanced Raman scattering signal by a varying magnetic field. OPTICS EXPRESS 2023; 31:12249-12260. [PMID: 37157388 DOI: 10.1364/oe.482479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Surface-enhanced Raman scattering (SERS) signals are fundamental for spectroscopy applications. However, existing substrates cannot perform a dynamically enhanced modulation of SERS signals. Herein, we developed a magnetically photonic chain-loading system (MPCLS) substrate by loading magnetically photonic nanochains of Fe3O4@SiO2 magnetic nanoparticles (MNPs) with Au nanoparticles (NPs). We achieved a dynamically enhanced modulation by applying an external stepwise magnetic field to the randomly dispersed magnetic photonic nanochains that gradually align in the analyte solution. The closely aligned nanochains create a higher number of hot spots by new neighboring Au NPs. Each chain represents a single SERS enhancement unit with both a surface plasmon resonance (SPR) effect and photonic property. The magnetic responsivity of MPCLS enables a rapid signal enhancement and tuning of the SERS enhancement factor.
Collapse
|
3
|
Meng B, Xie Y, Chen L, Wang H, Li M, Dong Z. Apex-Confined Plasmonic Tip for High Resolution Tip-Enhanced Raman Spectroscopic Imaging of Carbon Nanotubes. ACS APPLIED MATERIALS & INTERFACES 2023; 15:16984-16990. [PMID: 36946568 DOI: 10.1021/acsami.2c22624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
This paper reports a handy technical scheme to decorate atomic force microscopy (AFM) tips toward tip-enhanced Raman spectroscopy (TERS) applications. The major attraction of these homemade tips lies in that silver decoration can be confined at the apex of commercial tips by the means of an AFM-controlled electrochemical reaction. The reduction of Ag+ occurs in a highly sealed environment to secure the metal coating efficiency. Key factors include silver nitrate solution to provide Ag+, ambient relative humidity and temperature in a humidity cell, electric potential bias, and tip-surface distance. Subsequently, these silver-coated tips are evaluated for TERS measurement of carbon nanotubes (CNTs) so that both morphological and chemical characteristics of CNTs are concurrently obtained. The Raman spectra reveal that our plasmonic tip competently possesses an ∼30-fold local field signal increase and the corresponding TERS image laterally resolves at the single-pixel level.
Collapse
Affiliation(s)
- Bin Meng
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Yong Xie
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Le Chen
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| | - Haitao Wang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Ming Li
- School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, China
| | - Zhuxin Dong
- Department of Biomedical Engineering, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410013, China
| |
Collapse
|
4
|
Liang Y, Jin J, Wei Z, Wang M, Xiong J, Hou J, Tan W. Complexation mechanism of Pb 2+ at the ferrihydrite-water interface: The role of Al-substitution. CHEMOSPHERE 2022; 307:135627. [PMID: 35830935 DOI: 10.1016/j.chemosphere.2022.135627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/21/2022] [Accepted: 07/03/2022] [Indexed: 06/15/2023]
Abstract
Ferrihydrite is a poorly crystalline iron (hydr)oxide and highly efficient adsorbent for heavy metals. Al-substitution in ferrihydrite is ubiquitous in nature. However, the effect of Al-substitution on the surface reactivity of ferrihydrite remains unclear due to its low crystallinity. The present study aims to clarify the microstructure and interfacial reaction of Al-substituted ferrihydrite. Al-substitution had little effect on the morphology and surface site density of ferrihydrite, while the presence of ≡AlOH-0.5 sites resulted in higher proton affinity and surface positive charge of ferrihydrite. Besides, the affinity constant of Pb2+ adsorption on the surface of ferrihydrite decreased at higher Al content, which further decreased the adsorption performance of ferrihydrite for Pb2+. The modeling results revealed that bidentate complex was the dominant Pb complexation species on the surface of ferrihydrite, which was less affected by Al-substitution. The present study provides important insights into the effect of Al-substitution on the interfacial reaction at the ferrihydrite-water interface. The obtained parameters may facilitate the future advance of surface complexation model.
Collapse
Affiliation(s)
- Yu Liang
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China; State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jiezi Jin
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhiyuan Wei
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Mingxia Wang
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Juan Xiong
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jingtao Hou
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenfeng Tan
- State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| |
Collapse
|
5
|
Gradient SERS Substrates with Multiple Resonances for Analyte Screening: Fabrication and SERS Applications. Molecules 2022; 27:molecules27165097. [PMID: 36014328 PMCID: PMC9414786 DOI: 10.3390/molecules27165097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Surface-enhanced Raman spectroscopy (SERS) provides a strong enhancement to an inherently weak Raman signal, which strongly depends on the material, design, and fabrication of the substrate. Here, we present a facile method of fabricating a non-uniform SERS substrate based on an annealed thin gold (Au) film that offers multiple resonances and gap sizes within the same sample. It is not only chemically stable, but also shows reproducible trends in terms of geometry and plasmonic response. Scanning electron microscopy (SEM) reveals particle-like and island-like morphology with different gap sizes at different lateral positions of the substrate. Extinction spectra show that the plasmonic resonance of the nanoparticles/metal islands can be continuously tuned across the substrate. We observed that for the analytes 1,2-bis(4-pyridyl) ethylene (BPE) and methylene blue (MB), the maximum SERS enhancement is achieved at different lateral positions, and the shape of the extinction spectra allows for the correlation of SERS enhancement with surface morphology. Such non-uniform SERS substrates with multiple nanoparticle sizes, shapes, and interparticle distances can be used for fast screening of analytes due to the lateral variation of the resonances within the same sample.
Collapse
|
6
|
Malik B, Majumder S, Lorenzi R, Perelshtein I, Ejgenberg M, Paleari A, Nessim GD. Promising Electrocatalytic Water and Methanol Oxidation Reaction Activity by Nickel Doped Hematite/Surface Oxidized Carbon Nanotubes Composite Structures. Chempluschem 2022; 87:e202200036. [PMID: 35499139 DOI: 10.1002/cplu.202200036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/04/2022] [Indexed: 11/11/2022]
Abstract
Tailoring the precise construction of non-precious metals and carbon-based heterogeneous catalysts for electrochemical oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) is crucial for energy conversion applications. Herein, this work reports the composite of Ni doped Fe2 O3 (Ni-Fe2 O3 ) with mildly oxidized multi-walled CNT (O-CNT) as an outstanding Mott-Schottky catalyst for OER and MOR. O-CNT acts as a co-catalyst which effectively regulates the charge transfer in Ni-Fe2 O3 and thus enhances the electrocatalytic performance. Ni-Fe2 O3 /O-CNT exhibits a low onset potential of 260 mV and overpotential 310 mV @ 10 mA cm-2 for oxygen evolution. Being a Mott-Schottky catalyst, it achieves the higher flat band potential of -1.15 V with the carrier density of 0.173×1024 cm-3 . Further, in presence of 1 M CH3 OH, it delivers the MOR current density of 10 mA cm-2 at 1.46 V vs. RHE. The excellent electrocatalytic OER and MOR activity of Ni-Fe2 O3 /O-CNT could be attributed to the synergistic interaction between Ni-doped Fe2 O3 and O-CNT.
Collapse
Affiliation(s)
- Bibhudatta Malik
- Department of Chemistry and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, 52900, Israel
| | - Sumit Majumder
- Department of Chemistry and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, 52900, Israel
| | - Roberto Lorenzi
- Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 55, 20125, Milano, Italy
| | - Ilana Perelshtein
- Department of Chemistry and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, 52900, Israel
| | - Michal Ejgenberg
- Department of Chemistry and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, 52900, Israel
| | - Alberto Paleari
- Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 55, 20125, Milano, Italy
| | - Gilbert Daniel Nessim
- Department of Chemistry and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, 52900, Israel
| |
Collapse
|
7
|
Itasaka H, Liu M, Kojima R, Yoshikawa T, Nishikawa M, Nishi M, Hamamoto K. Single-particle Observation of Detonation Nanodiamonds by Tip-enhanced Raman Spectroscopy. CHEM LETT 2021. [DOI: 10.1246/cl.210042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hiroki Itasaka
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya, Aichi 463-8560, Japan
| | - Ming Liu
- Incubation Research Center, Innovation and Business Development Headquarters, Daicel Corporation, 1239 Shinzaike, Aboshi-ku, Himeji, Hyogo 671-1283, Japan
| | - Ryota Kojima
- Incubation Research Center, Innovation and Business Development Headquarters, Daicel Corporation, 1239 Shinzaike, Aboshi-ku, Himeji, Hyogo 671-1283, Japan
| | - Taro Yoshikawa
- Incubation Research Center, Innovation and Business Development Headquarters, Daicel Corporation, 1239 Shinzaike, Aboshi-ku, Himeji, Hyogo 671-1283, Japan
| | - Masahiro Nishikawa
- Incubation Research Center, Innovation and Business Development Headquarters, Daicel Corporation, 1239 Shinzaike, Aboshi-ku, Himeji, Hyogo 671-1283, Japan
| | - Masayuki Nishi
- Department of Mechanical and Electrical System Engineering, Faculty of Engineering, Kyoto University of Advanced Science, 18 Yamanouchi Gotanda-cho, Ukyo-ku, Kyoto 615-8577, Japan
| | - Koichi Hamamoto
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya, Aichi 463-8560, Japan
| |
Collapse
|
8
|
Kim M, Ha J, Shin N, Kim YT, Choi J. Self-activated anodic nanoporous stainless steel electrocatalysts with high durability for the hydrogen evolution reaction. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.137315] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
9
|
Zhang K, Lee TH, Bubach B, Jang HW, Ostadhassan M, Choi JW, Shokouhimehr M. Graphite carbon-encapsulated metal nanoparticles derived from Prussian blue analogs growing on natural loofa as cathode materials for rechargeable aluminum-ion batteries. Sci Rep 2019; 9:13665. [PMID: 31541195 PMCID: PMC6754498 DOI: 10.1038/s41598-019-50154-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/27/2019] [Indexed: 12/02/2022] Open
Abstract
Aluminum-ion batteries (AIBs) are attracting increasing attention as a potential energy storage system owing to the abundance of Al sources and high charge density of Al3+. However, suitable cathode materials to further advance high-performing AIBs are unavailable. Therefore, we demonstrated the compatibility of elemental metal nanoparticles (NPs) as cathode materials for AIBs. Three types of metal NPs (Co@C, Fe@C, CoFe@C) were formed by in-situ growing Prussian blue analogs (PBAs, Co[Co(CN)6], Fe[Fe(CN)6] and Co[Fe(CN)6]) on a natural loofa (L) by a room-temperature wet chemical method in aqueous bath, followed by a carbonization process. The employed L effectively formed graphite C-encapsulated metal NPs after heat treatment. The discharge capacity of CoFe@C was superior (372 mAh g−1) than others (103 mAh g−1 for Co@C and 75 mAh g−1 for Fe@C). The novel design results in CoFe@C with an outstanding long-term charge/discharge cycling performance (over 1,000 cycles) with a Coulombic efficiency of 94.1%. Ex-situ X-ray diffraction study indicates these metal NP capacities are achieved through a solid-state diffusion-limited Al storage process. This novel design for cathode materials is highly significant for the further development of advanced AIBs in the future.
Collapse
Affiliation(s)
- Kaiqiang Zhang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea.,Electronic Materials Center, Korea Institute of Science and Technology (KIST), Seoul, 136-791, South Korea
| | - Tae Hyung Lee
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
| | - Bailey Bubach
- Department of Petroleum Engineering, University of North Dakota, Grand Forks, ND, 58202, United States
| | - Ho Won Jang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
| | - Mehdi Ostadhassan
- Department of Petroleum Engineering, University of North Dakota, Grand Forks, ND, 58202, United States.
| | - Ji-Won Choi
- Electronic Materials Center, Korea Institute of Science and Technology (KIST), Seoul, 136-791, South Korea.
| | - Mohammadreza Shokouhimehr
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea. .,Department of Petroleum Engineering, University of North Dakota, Grand Forks, ND, 58202, United States.
| |
Collapse
|
10
|
Li H, Ban L, Niu Z, Huang X, Meng P, Han X, Zhang Y, Zhang H, Zhao Y. Application of Cu xO-Fe yO z Nanocatalysts in Ethynylation of Formaldehyde. NANOMATERIALS 2019; 9:nano9091301. [PMID: 31514403 PMCID: PMC6781078 DOI: 10.3390/nano9091301] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/05/2019] [Accepted: 09/08/2019] [Indexed: 11/17/2022]
Abstract
Composite nanomaterials have been widely used in catalysis because of their attractive properties and various functions. Among them, the preparation of composite nanomaterials by redox has attracted much attention. In this work, pure Cu2O was prepared by liquid phase reduction with Cu(NO3)2 as the copper source, NaOH as a precipitator, and sodium ascorbate as the reductant. With Fe(NO3)3 as the iron source and solid-state phase reaction between Fe3+ and Cu2O, CuxO-FeyOz nanocatalysts with different Fe/Cu ratios were prepared. The effects of the Fe/Cu ratio on the structure of CuxO-FeyOz nanocatalysts were studied by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet confocal Raman (Raman), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS, XAES), and hydrogen temperature-programmed reduction (H2-TPR). Furthermore, the structure–activity relationship between the structure of CuxO-FeyOz nanocatalysts and the performance of formaldehyde ethynylation was discussed. The results show that Fe3+ deposited preferentially on the edges and corners of the Cu2O surface, and a redox reaction between Fe3+ and Cu+ occurred, forming CuxO-FeyOz nanoparticles containing Cu+, Cu2+, Fe2+, and Fe3+. With the increase of the Fe/Cu ratio, the content of CuxO-FeyOz increased. When the Fe/Cu ratio reached 0.8, a core–shell structure with Cu2O inside and a CuxO-FeyOz coating on the outside was formed. Because of the large physical surface area and the heterogeneous structure formed by CuxO-FeyOz, the formation of nonactive Cu metal is inhibited, and the most active species of Cu+ are exposed on the surface, showing the best formaldehyde ethynylation activity.
Collapse
Affiliation(s)
- Haitao Li
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Lijun Ban
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Zhuzhu Niu
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Xin Huang
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Pingfan Meng
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Xudong Han
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Yin Zhang
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Hongxi Zhang
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| | - Yongxiang Zhao
- Engineering Research Center of Ministry of Education for Fine Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
| |
Collapse
|
11
|
Testa-Anta M, Ramos-Docampo MA, Comesaña-Hermo M, Rivas-Murias B, Salgueiriño V. Raman spectroscopy to unravel the magnetic properties of iron oxide nanocrystals for bio-related applications. NANOSCALE ADVANCES 2019; 1:2086-2103. [PMID: 36131987 PMCID: PMC9418671 DOI: 10.1039/c9na00064j] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/22/2019] [Indexed: 05/05/2023]
Abstract
Iron oxide nanocrystals have become a versatile tool in biomedicine because of their low cytotoxicity while offering a wide range of tuneable magnetic properties that may be implemented in magnetic separation, drug and heat delivery and bioimaging. These capabilities rely on the unique magnetic features obtained when combining different iron oxide phases, so that an important portfolio of magnetic properties can be attained by the rational design of multicomponent nanocrystals. In this context, Raman spectroscopy is an invaluable and fast-performance tool to gain insight into the different phases forming part of the nanocrystals to be used, allowing correlation of the magnetic properties with the envisaged bio-related applications.
Collapse
Affiliation(s)
- Martín Testa-Anta
- Departamento de Física Aplicada, Universidade de Vigo 36310 Vigo Spain
| | | | - Miguel Comesaña-Hermo
- Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR CNRS 7086 75013 Paris France
| | | | | |
Collapse
|
12
|
Rahaman M, Milekhin AG, Mukherjee A, Rodyakina EE, Latyshev AV, Dzhagan VM, Zahn DRT. The role of a plasmonic substrate on the enhancement and spatial resolution of tip-enhanced Raman scattering. Faraday Discuss 2019; 214:309-323. [PMID: 30839033 DOI: 10.1039/c8fd00142a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Since the first report in the early 2000s, there have been several experimental configurations that have demonstrated enhancement and spatial resolution of tip-enhanced Raman spectroscopy (TERS). The combination of a plasmonic substrate and a metallic tip is one suitable approach to achieve even higher enhancement and lateral resolution. In this contribution, we demonstrate TERS on a monolayer of MoS2 on an array of Au nanodisks. The Au nanodisks were prepared by electron beam writing. Thereafter, MoS2 was transferred onto the plasmonic substrate via the exfoliation technique. We witness an unprecedented enhancement and spatial resolution in the experiments. In the TERS image a ring-like shape is observed that matches the edges of the nanodisks. TERS enhancement at the edges is about 170 times stronger than at the center of the nanodisks. For a better understanding of the experimental results, finite element method (FEM) simulations were employed to simulate the TERS image of the MoS2/plasmonic heterostructure. Our calculations show a higher electric field concentration at the edges that exponentially decays to the center. Therefore, it reproduces the ring-like shape of the experimental image. Moreover, the calculations suggest a TERS enhancement of 135 at the edges compared to the center, which is in very good agreement with the experimental data. According to our calculations, the spatial resolution is also increased at the edges. For comparison, FEM simulations of a tip-flat metal substrate system (conventional gap-mode TERS) were carried out. The calculations confirmed a 110 times stronger enhancement at the edges of the nanodisks than that of conventional gap-mode TERS and explained the experimental maps. Our results provide not only a deeper understanding of the TERS mechanism of this heterostructure, but can also help in realizing highly efficient TERS experiments using similar systems.
Collapse
Affiliation(s)
- Mahfujur Rahaman
- Semiconductor Physics, Chemnitz University of Technology, D-09107 Chemnitz, Germany.
| | - Alexander G Milekhin
- Rzhanov Institute of Semiconductor Physics RAS, Lavrentiev Ave. 13, 630090 Novosibirsk, Russia and Novosibirsk State University, Pirogov 2, 630090 Novosibirsk, Russia
| | - Ashutosh Mukherjee
- Semiconductor Physics, Chemnitz University of Technology, D-09107 Chemnitz, Germany.
| | - Ekaterina E Rodyakina
- Rzhanov Institute of Semiconductor Physics RAS, Lavrentiev Ave. 13, 630090 Novosibirsk, Russia and Novosibirsk State University, Pirogov 2, 630090 Novosibirsk, Russia
| | - Alexander V Latyshev
- Rzhanov Institute of Semiconductor Physics RAS, Lavrentiev Ave. 13, 630090 Novosibirsk, Russia and Novosibirsk State University, Pirogov 2, 630090 Novosibirsk, Russia
| | - Volodymyr M Dzhagan
- Semiconductor Physics, Chemnitz University of Technology, D-09107 Chemnitz, Germany. and Lashkaryov Institute of Semiconductors Physics, National Academy of Sciences of Ukraine, 03028 Kyiv, Ukraine
| | - Dietrich R T Zahn
- Semiconductor Physics, Chemnitz University of Technology, D-09107 Chemnitz, Germany.
| |
Collapse
|
13
|
McClure JP, Grew KN, Baker DR, Gobrogge E, Das N, Chu D. Harvesting resonantly-trapped light for small molecule oxidation reactions at the Au/α-Fe 2O 3 interface. NANOSCALE 2018; 10:7833-7850. [PMID: 29664495 DOI: 10.1039/c8nr01330f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Plasmonic metal nanoparticles (NPs) extend the overall light absorption of semiconductor materials. However, it is not well understood how coupling metal NPs to semiconductors alters the photo-electrochemical activity of small molecule oxidation (SMO) reactions. Different photo-anode electrodes comprised of Au NPs and α-Fe2O3 are designed to elucidate how the coupling plays not only a role in the water oxidation reaction (WO) but also performs for different SMO reactions. In this regard, Au NPs are inserted at specific regions within and/or on α-Fe2O3 layers created with a sequential electron beam evaporation method and multiple annealing treatments. The SMO and WO reactions are probed with broad-spectrum irradiation experiments with an emphasis on light-driven enhancements above and below the α-Fe2O3 band gap. Thin films of α-Fe2O3 supported on a gold back reflective layer resonantly-traps incident light leading to enhanced SMO/WO conversion efficiencies at high overpotential (η) for above band-gap excitations with no SMO activity observed at low η. In contrast, a substantial increase in the light-driven SMO activity is observed at low η, as well as for below band-gap excitations when sufficiently thin α-Fe2O3 films are decorated with Au NPs at the solution-electrode interface. The enhanced photo-catalytic activity is correlated with increased surface oxygen content (hydroxyl groups) at the Au/α-Fe2O3 interface, as well as simulated volume-integrated near-field enhancements over select regions of the Au/α-Fe2O3 interface providing an important platform for future SMO/WO photo-electrocatalyst development.
Collapse
Affiliation(s)
- Joshua P McClure
- U.S. Army Research Laboratory, Adelphi, MD, 2800 Powder Mill Road, Adelphi, MD 20783, USA.
| | | | | | | | | | | |
Collapse
|
14
|
Deckert-Gaudig T, Taguchi A, Kawata S, Deckert V. Tip-enhanced Raman spectroscopy - from early developments to recent advances. Chem Soc Rev 2018. [PMID: 28640306 DOI: 10.1039/c7cs00209b] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An analytical technique operating at the nanoscale must be flexible regarding variable experimental conditions while ideally also being highly specific, extremely sensitive, and spatially confined. In this respect, tip-enhanced Raman scattering (TERS) has been demonstrated to be ideally suited to, e.g., elucidating chemical reaction mechanisms, determining the distribution of components and identifying and localizing specific molecular structures at the nanometre scale. TERS combines the specificity of Raman spectroscopy with the high spatial resolution of scanning probe microscopies by utilizing plasmonic nanostructures to confine the incident electromagnetic field and increase it by many orders of magnitude. Consequently, molecular structure information in the optical near field that is inaccessible to other optical microscopy methods can be obtained. In this general review, the development of this still-young technique, from early experiments to recent achievements concerning inorganic, organic, and biological materials, is addressed. Accordingly, the technical developments necessary for stable and reliable AFM- and STM-based TERS experiments, together with the specific properties of the instruments under different conditions, are reviewed. The review also highlights selected experiments illustrating the capabilities of this emerging technique, the number of users of which has steadily increased since its inception in 2000. Finally, an assessment of the frontiers and new concepts of TERS, which aim towards rendering it a general and widely applicable technique that combines the highest possible lateral resolution and extreme sensitivity, is provided.
Collapse
|
15
|
Milekhin AG, Rahaman M, Rodyakina EE, Latyshev AV, Dzhagan VM, Zahn DRT. Giant gap-plasmon tip-enhanced Raman scattering of MoS 2 monolayers on Au nanocluster arrays. NANOSCALE 2018; 10:2755-2763. [PMID: 29308796 DOI: 10.1039/c7nr06640f] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this article, we present the results of a gap-plasmon tip-enhanced Raman scattering study of MoS2 monolayers deposited on a periodic array of Au nanostructures on a silicon substrate forming a two dimensional (2D) crystal/plasmonic heterostructure. We observe a giant Raman enhancement of the phonon modes in the MoS2 monolayer located in the plasmonic gap between the Au tip apex and Au nanoclusters. Tip-enhanced Raman mapping allows us to determine the gap-plasmon field distribution responsible for the formation of hot spots. These hot spots provide an unprecedented giant Raman enhancement of 5.6 × 108 and a spatial resolution as small as 2.3 nm under ambient conditions. Moreover, due to strong hot electron doping in the order of 1.8 × 1013 cm-2, we observe a structural change of MoS2 from the 2H to the 1T phase. Owing to the very good spatial resolution, we are able to spatially resolve those doping sites. To the best of our knowledge, this is the first time reporting of such a phenomenon with nm spatial resolution. Our results will open the perspectives of optical diagnostics with nanometer resolution for many other 2D materials.
Collapse
Affiliation(s)
- Alexander G Milekhin
- Rzhanov Institute of Semiconductor Physics RAS, Lavrentiev Ave. 13, 630090, Novosibirsk, Russia.
| | | | | | | | | | | |
Collapse
|
16
|
Affiliation(s)
- Lifu Xiao
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Zachary D Schultz
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| |
Collapse
|
17
|
Gutsev GL, Belay KG, Gutsev LG, Ramachandran BR, Jena P. Effect of hydrogenation on the structure and magnetic properties of an iron oxide cluster. Phys Chem Chem Phys 2018; 20:4546-4553. [DOI: 10.1039/c7cp08224j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogenation of an iron oxide particle influences the geometrical topology and total magnetic moment and invokes different superexchange mechanisms.
Collapse
Affiliation(s)
- G. L. Gutsev
- Department of Physics
- Florida A&M University
- Tallahassee
- USA
| | - K. G. Belay
- Department of Physics
- Florida A&M University
- Tallahassee
- USA
| | - L. G. Gutsev
- Department of Physics
- Virginia Commonwealth University
- Richmond
- USA
| | | | - P. Jena
- Department of Physics
- Virginia Commonwealth University
- Richmond
- USA
| |
Collapse
|
18
|
Shanei A, Sazgarnia A, Dolat E, Hojaji-Najafabadi L, Sehhati M, Baradaran-Ghahfarokhi M. Dual Function of Gold Nanoparticles in Synergism with Mitoxantrone and Microwave Hyperthermia Against Melanoma Cells. Asian Pac J Cancer Prev 2017; 18:2911-2917. [PMID: 29172258 PMCID: PMC5773770 DOI: 10.22034/apjcp.2017.18.11.2911] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background: This study was performed to evaluate any synergetic effects of mitoxantrone (MX) and gold nanoparticles (GNPs) as dual therapeutic approach, along with microwave (MW) hyperthermia for melanoma cancer. Methods: Various tests were performed on the DFW melanoma cell line in the presence of MX and different concentrations of GNPs, with and without MW irradiation. MTT [3-(4,5-dimethylthiazol–2-yl)-2,5-iphenyltetrazolium bromide] assays were conducted to evaluate the effectiveness of the used therapeutic methods in terms of cell survival. Relative lethal synergism (RLS) was calculated as the ratio of cell death following hyperthermia in the presence of a treatment agent to that after applying hyperthermia in the absence of the same treatment agent. Results: Results showed MX and GNPs under MW irradiation to provide maximum cell death (P < 0.001 compared to the other groups). The mean RLS for MW hyperthermia along with the MX-GNP combination was 4.14, whereas in the absence of GNP the value for MX chemotherapy was 0.94. Conclusion: MX chemotherapy in the presence of different concentrations of GNP did not alter cell survival as compared to in its absence.
Collapse
Affiliation(s)
- Ahmad Shanei
- Department of Medical Physics and Medical Engineering and Student Research Committe, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ameneh Sazgarnia
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Elham Dolat
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Leila Hojaji-Najafabadi
- Nanotechnology Department, Faculty of Advanced Sciences and Technologies, Isfahan University, Isfahan, Iran
| | - Mohammadreza Sehhati
- Department of Bioelectric and Biomedical Engineering, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Milad Baradaran-Ghahfarokhi
- Department of Medical Physics and Medical Engineering and Student Research Committe, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Medical Radiation Engineering, Faculty of Advanced Sciences and Technologies, Isfahan University, Isfahan, Iran
| |
Collapse
|
19
|
Mochizuki M, Lkhamsuren G, Suthiwanich K, Mondarte EA, Yano TA, Hara M, Hayashi T. Damage-free tip-enhanced Raman spectroscopy for heat-sensitive materials. NANOSCALE 2017; 9:10715-10720. [PMID: 28681893 DOI: 10.1039/c7nr02398g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report a method to establish experimental conditions for tip-enhanced Raman spectroscopy (TERS) with low thermal and mechanical damage to samples. In this method, we monitor the thermal desorption of thiol molecules from a gold-coated probe of an atomic force microscope (AFM) via TERS spectra. Temperatures for desorption of thiol molecules (60-100 °C) from gold surfaces cover the temperature range for degradation of heat-sensitive biomaterials (e.g. proteins). By monitoring the desorption of the thiols on the probe, we can estimate the power of an excitation laser for the samples to reach their critical temperatures for thermal degradation. Furthermore, we also found that an active oscillation of AFM cantilevers significantly promotes the heat transfer from the probe to the surrounding medium. This enables us to employ a higher power density of the excitation laser, resulting in a stronger Raman signal compared with the signal obtained with a contact mode. We propose that this combinatory method is effective in acquiring strong TERS signals while suppressing thermal and mechanical damage to soft and heat-sensitive samples.
Collapse
Affiliation(s)
- Masahito Mochizuki
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8502, Japan.
| | | | | | | | | | | | | |
Collapse
|
20
|
Nikzad S, Mahmoudi G, Amini P, Baradaran-Ghahfarokhi M, Vahdat-Moaddab A, Sharafi SM, Hojaji-Najafabadi L, Hosseinzadeh A. Effects of radiofrequency radiation in the presence of gold nanoparticles for the treatment of renal cell carcinoma. J Renal Inj Prev 2017; 6:103-108. [PMID: 28497084 PMCID: PMC5423275 DOI: 10.15171/jrip.2017.20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/18/2016] [Indexed: 01/13/2023] Open
Abstract
Introduction: The most common type of kidney cancer is renal cell carcinoma (RCC), which accounts for more than 80% of all kidney cancers.
Objectives: The aim of this study was to evaluate the effects of radiofrequency (RF) radiation in the presence of gold nanoparticles (GNPs) for the treatment of RCC.
Materials and Methods: Human embryonic kidney (HEK) cancer cells were divided into 6 groups. Various tests were performed on HEK cells in the presence of RF and GNPs. In order to investigate the radiation effects on the cells’ survival, MTT [3-(4,5-dimethylthiazol–2-yl)-2,5-iphenyltetrazolium bromide] assay was performed at different days during and post-irradiation period. The repeated measure analysis of variance (ANOVA) method was used for statistical analysis of the cells’ survival using SPSS version 16.0. A significant level of 0.05 was considered to the tests.
Results: Using the ANOVA test, a significant decrease in cell’s survival was seen in the RF exposed group 3 compared to the control group (P=0.035). While, differences were not significant between RF exposed group 2 and the control group (P>0.05). A significant decrease in cell’s survival in the RF exposed groups 5 (P=0.025) and 6 (P=0.018) at the presence of GNP compared to the control group was seen.
Conclusion: Results of this study showed that, this method can be efficiently used for RCC treatment as an alternative to nephrectomy. More follow up in vivo studies on mammalians are needed to investigate the potential of the presented method for clinical applications.
Collapse
Affiliation(s)
- Safoora Nikzad
- Department of Medical Physics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Golshan Mahmoudi
- Medical Physics Department, School of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Payam Amini
- Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Milad Baradaran-Ghahfarokhi
- Department of Medical Physics and Medical Engineering & Students Research Committee, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Department of Medical Radiation Engineering, Faculty of Advanced Sciences & Technologies, Isfahan University, Isfahan, Iran
| | | | - Seyedeh Maryam Sharafi
- Infectious Disease and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Leila Hojaji-Najafabadi
- Nanotechnology Department, Faculty of Advanced Sciences and Technologies, Isfahan University, Isfahan, Iran
| | - Ali Hosseinzadeh
- Research Center for Modeling in Health, Institute for Future Studies in Health, Kerman University of Medical Sciences, Kerman, and, Epidemiology and Biostatistics Department, School of Health, Sabzevar University of Medical Sciences, Sabzevar, Iran
| |
Collapse
|
21
|
Ofner J, Deckert-Gaudig T, Kamilli KA, Held A, Lohninger H, Deckert V, Lendl B. Tip-Enhanced Raman Spectroscopy of Atmospherically Relevant Aerosol Nanoparticles. Anal Chem 2016; 88:9766-9772. [DOI: 10.1021/acs.analchem.6b02760] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Johannes Ofner
- Institute
of Chemical Technologies and Analytics, TU Wien, Getreidemarkt
9, 1060 Vienna, Austria
| | - Tanja Deckert-Gaudig
- Leibniz Institute of Photonic Technology, Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - Katharina A. Kamilli
- Atmospheric Chemistry, University of Bayreuth, Dr.-Hans-Frisch-Straße 1-3, D-95448 Bayreuth, Germany
| | - Andreas Held
- Atmospheric Chemistry, University of Bayreuth, Dr.-Hans-Frisch-Straße 1-3, D-95448 Bayreuth, Germany
| | - Hans Lohninger
- Institute
of Chemical Technologies and Analytics, TU Wien, Getreidemarkt
9, 1060 Vienna, Austria
| | - Volker Deckert
- Leibniz Institute of Photonic Technology, Albert-Einstein-Strasse 9, 07745 Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, University of Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Bernhard Lendl
- Institute
of Chemical Technologies and Analytics, TU Wien, Getreidemarkt
9, 1060 Vienna, Austria
| |
Collapse
|
22
|
Gutsev GL, Belay KG, Gutsev LG, Ramachandran BR. Structure and properties of iron oxide clusters: From Fe
6
to Fe
6
O
20
and from Fe
7
to Fe
7
O
24. J Comput Chem 2016; 37:2527-36. [DOI: 10.1002/jcc.24478] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/05/2016] [Accepted: 08/10/2016] [Indexed: 12/14/2022]
Affiliation(s)
| | - Kalayu G. Belay
- Department of PhysicsFlorida A&M UniversityTallahassee Florida32307
| | - Lavrenty G. Gutsev
- Department of Chemistry and BiochemistryFlorida State UniversityTallahassee, Florida32306
| | - Bala R. Ramachandran
- College of Engineering & Science, Louisiana Tech UniversityRuston Louisiana71272
| |
Collapse
|
23
|
Nanometal Skin of Plasmonic Heterostructures for Highly Efficient Near-Field Scattering Probes. Sci Rep 2016; 6:31113. [PMID: 27502178 PMCID: PMC4977468 DOI: 10.1038/srep31113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/14/2016] [Indexed: 01/06/2023] Open
Abstract
In this work, atomic force microscopy probes are functionalized by virtue of self-assembling monolayers of block copolymer (BCP) micelles loaded either with clusters of silver nanoparticles or bimetallic heterostructures consisting of mixed species of silver and gold nanoparticles. The resulting self-organized patterns allow coating the tips with a sort of nanometal skin made of geometrically confined nanoislands. This approach favors the reproducible engineering and tuning of the plasmonic properties of the resulting structured tip by varying the nanometal loading of the micelles. The newly conceived tips are applied for experiments of tip-enhanced Raman scattering (TERS) spectroscopy and scattering-type scanning near-field optical microscopy (s-SNOM). TERS and s-SNOM probe characterizations on several standard Raman analytes and patterned nanostructures demonstrate excellent enhancement factor with the possibility of fast scanning and spatial resolution <12 nm. In fact, each metal nanoisland consists of a multiscale heterostructure that favors large scattering and near-field amplification. Then, we verify the tips to allow challenging nongap-TER spectroscopy on thick biosamples. Our approach introduces a synergistic chemical functionalization of the tips for versatile inclusion and delivery of plasmonic nanoparticles at the tip apex, which may promote the tuning of the plasmonic properties, a large enhancement, and the possibility of adding new degrees of freedom for tip functionalization.
Collapse
|
24
|
Gutsev GL, Belay KG, Bozhenko KV, Gutsev LG, Ramachandran BR. A comparative study of small 3d-metal oxide (FeO)n, (CoO)n, and (NiO)n clusters. Phys Chem Chem Phys 2016; 18:27858-27867. [DOI: 10.1039/c6cp03241a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Geometrical and electronic structures of the 3d-metal oxide clusters (FeO)n, (CoO)n, and (NiO)n are computed using density functional theory with the generalized gradient approximation in the range of 1 ≤ n ≤ 10.
Collapse
Affiliation(s)
- G. L. Gutsev
- Department of Physics
- Florida A&M University
- Tallahassee
- USA
| | - K. G. Belay
- Department of Physics
- Florida A&M University
- Tallahassee
- USA
| | - K. V. Bozhenko
- Institute of Problems of Chemical Physics
- Russian Academy of Sciences
- Chernogolovka 142432
- Russia
- Department of Physical and Colloid Chemistry
| | - L. G. Gutsev
- Department of Chemistry and Biochemistry
- Florida State University
- Tallahassee
- USA
| | | |
Collapse
|
25
|
Iacovita C, Stiufiuc R, Radu T, Florea A, Stiufiuc G, Dutu A, Mican S, Tetean R, Lucaciu CM. Polyethylene Glycol-Mediated Synthesis of Cubic Iron Oxide Nanoparticles with High Heating Power. NANOSCALE RESEARCH LETTERS 2015; 10:391. [PMID: 26446074 PMCID: PMC4596149 DOI: 10.1186/s11671-015-1091-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 09/27/2015] [Indexed: 05/04/2023]
Abstract
Iron oxide magnetic nanoparticles (IOMNPs) have been successfully synthesized by means of solvothermal reduction method employing polyethylene glycol (PEG200) as a solvent. The as-synthesized IOMNPs are poly-dispersed, highly crystalline, and exhibit a cubic shape. The size of IOMNPs is strongly dependent on the reaction time and the ration between the amount of magnetic precursor and PEG200 used in the synthesis method. At low magnetic precursor/PEG200 ratio, the cubic IOMNPs coexist with polyhedral IOMNPs. The structure and morphology of the IOMNPs were thoroughly investigated by using a wide range of techniques: TEM, XRD, XPS, FTIR, and RAMAN. XPS analysis showed that the IOMNPs comprise a crystalline magnetite core bearing on the outer surface functional groups from PEG200 and acetate. The presence of physisorbed PEG200 on the IOMNP surface is faintly detected through FT-IR spectroscopy. The surface of IOMNPs undergoes oxidation into maghemite as proven by RAMAN spectroscopy and the occurrence of satellite peaks in the Fe2p XP spectra. The magnetic studies performed on powder show that the blocking temperature (TB) of IOMNPs is around 300 K displaying a coercive field in between 160 and 170 Oe. Below the TB, the field-cooled (FC) curves turn concave and describe a plateau indicating that strong magnetic dipole-dipole interactions are manifested in between IOMNPs. The specific absorption rate (SAR) values increase with decreasing nanoparticle concentrations for the IOMNPs dispersed in water. The SAR dependence on the applied magnetic field, studied up to magnetic field amplitude of 60 kA/m, presents a sigmoid shape with saturation values up to 1700 W/g. By dispersing the IOMNPs in PEG600 (liquid) and PEG1000 (solid), it was found that the SAR values decrease by 50 or 75 %, indicating that the Brownian friction within the solvent was the main contributor to the heating power of IOMNPs.
Collapse
Affiliation(s)
- Cristian Iacovita
- Department of Pharmaceutical Physics-Biophysics, Faculty of Pharmacy, "Iuliu Hatieganu" University of Medicine and Pharmacy, Pasteur 6, 400349, Cluj-Napoca, Romania.
| | - Rares Stiufiuc
- Department of Pharmaceutical Physics-Biophysics, Faculty of Pharmacy, "Iuliu Hatieganu" University of Medicine and Pharmacy, Pasteur 6, 400349, Cluj-Napoca, Romania.
| | - Teodora Radu
- Interdisciplinary Research Institute on Bio-Nano-Science, Treboniu Laurian 42, 400271, Cluj-Napoca, Romania.
- National Institute of Research and Development for Isotopic and Molecular Technologies, Donath 65-103, 400293, Cluj-Napoca, Romania.
| | - Adrian Florea
- Department of Cell and Molecular Biology, Faculty of Medicine, "Iuliu Hatieganu" University of Medicine and Pharmacy, Pasteur 6, 400349, Cluj-Napoca, Romania.
| | - Gabriela Stiufiuc
- Faculty of Physics, "Babes Bolyai" University, Kogalniceanu 1, 400084, Cluj-Napoca, Romania.
| | - Alina Dutu
- Department of Physiology, Faculty of Medicine, "Iuliu Hatieganu" University of Medicine and Pharmacy, Clinicilor 1, 400006, Cluj-Napoca, Romania.
| | - Sever Mican
- Faculty of Physics, "Babes Bolyai" University, Kogalniceanu 1, 400084, Cluj-Napoca, Romania.
| | - Romulus Tetean
- Faculty of Physics, "Babes Bolyai" University, Kogalniceanu 1, 400084, Cluj-Napoca, Romania.
| | - Constantin M Lucaciu
- Department of Pharmaceutical Physics-Biophysics, Faculty of Pharmacy, "Iuliu Hatieganu" University of Medicine and Pharmacy, Pasteur 6, 400349, Cluj-Napoca, Romania.
| |
Collapse
|
26
|
Langelüddecke L, Singh P, Deckert V. Exploring the Nanoscale: Fifteen Years of Tip-Enhanced Raman Spectroscopy. APPLIED SPECTROSCOPY 2015; 69:1357-71. [PMID: 26554759 DOI: 10.1366/15-08014] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Spectroscopic methods with high spatial resolution are essential to understand the physical and chemical properties of nanoscale materials including biological and chemical materials. Tip-enhanced Raman spectroscopy (TERS) is a combination of surface-enhanced Raman spectroscopy (SERS) and scanning probe microscopy (SPM), which can provide high-resolution topographic and spectral information simultaneously below the diffraction limit of light. Even examples of sub-nanometer resolution have been demonstrated. This review intends to give an introduction to TERS, focusing on its basic principle and the experimental setup, the strengths followed by recent applications, developments, and perspectives in this field.
Collapse
Affiliation(s)
- Lucas Langelüddecke
- Institute of Physical Chemistry and Abbe Center of Photonics, University of Jena, Helmholtzweg 4, D-07743 Jena, Germany
| | | | | |
Collapse
|