401
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Liu B, Wang D, Shi C, Crozier KB, Yang T. Vertical optical antennas integrated with spiral ring gratings for large local electric field enhancement and directional radiation. OPTICS EXPRESS 2011; 19:10049-56. [PMID: 21643263 DOI: 10.1364/oe.19.010049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We propose a device for reproducible achievement of enormous enhancement of local electric field intensities. In each device, a metallic spiral ring grating is employed for efficient excitation of local surface plasmon resonance in the tiny gap of a vertically oriented optical antenna. Radiation from the optical antenna is collimated by the ring grating which facilitates efficient collection. As a numerical example, for a gold nanosphere placed one nanometer above the center of a gold spiral ring grating, our simulations predict an increase in local electric field intensity of up to seven orders of magnitude compared to planewave illumination, and collection efficiencies of up to 68% by an objective with a numerical aperture of 0.7. Single molecule SERS application is discussed.
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Affiliation(s)
- Baoan Liu
- National Key Laboratory of Nano/Micro Fabrication Technology, University of Michigan – Shanghai Jiao Tong University Joint Institute, Shanghai 200240, China
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402
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Liu N, Tang ML, Hentschel M, Giessen H, Alivisatos AP. Nanoantenna-enhanced gas sensing in a single tailored nanofocus. NATURE MATERIALS 2011; 10:631-6. [PMID: 21572410 DOI: 10.1038/nmat3029] [Citation(s) in RCA: 434] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 04/18/2011] [Indexed: 05/20/2023]
Abstract
Metallic nanostructures possess plasmonic resonances that spatially confine light on the nanometre scale. In the ultimate limit of a single nanostructure, the electromagnetic field can be strongly concentrated in a volume of only a few hundred nm(3) or less. This optical nanofocus is ideal for plasmonic sensing. Any object that is brought into this single spot will influence the optical nanostructure resonance with its dielectric properties. Here, we demonstrate antenna-enhanced hydrogen sensing at the single-particle level. We place a single palladium nanoparticle near the tip region of a gold nanoantenna and detect the changing optical properties of the system on hydrogen exposure by dark-field microscopy. Our method avoids any inhomogeneous broadening and statistical effects that would occur in sensors based on nanoparticle ensembles. Our concept paves the road towards the observation of single catalytic processes in nanoreactors and biosensing on the single-molecule level.
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Affiliation(s)
- Na Liu
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
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403
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Rycenga M, Xia X, Moran CH, Zhou F, Qin D, Li ZY, Xia Y. Generation of Hot Spots with Silver Nanocubes for Single-Molecule Detection by Surface-Enhanced Raman Scattering. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101632] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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404
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Han X, Goebl J, Lu Z, Yin Y. Role of salt in the spontaneous assembly of charged gold nanoparticles in ethanol. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5282-5289. [PMID: 21466161 DOI: 10.1021/la200459t] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This paper investigates the role of salt in the spontaneous linear assembly of charged gold nanoparticles in ethanol and attempts to clear up a misunderstanding on the role of ethanol in this process. Many prior reports have noted that the addition of ethanol to an aqueous solution of gold nanoparticles causes their aggregation into linear assemblies. It was therefore believed that ethanol plays the determining role during the assembly process. In this work, we carried out systematic studies which indicate that residual salt in conjunction with ethanol, instead of ethanol itself, induces the assembly of gold nanoparticles in ethanol. In the absence of salt, gold nanoparticles can be well dispersed in an ethanol solution. Furthermore, we find that the chainlike assemblies can disassemble upon dilution of the salt or the evaporation of ethanol if the gold nanoparticles are protected with a sufficiently strong ligand.
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Affiliation(s)
- Xiaogang Han
- Department of Chemistry, University of California, Riverside, California 92521, United States
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405
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Rycenga M, Xia X, Moran CH, Zhou F, Qin D, Li ZY, Xia Y. Generation of hot spots with silver nanocubes for single-molecule detection by surface-enhanced Raman scattering. Angew Chem Int Ed Engl 2011; 50:5473-7. [PMID: 21542081 DOI: 10.1002/anie.201101632] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Indexed: 11/12/2022]
Affiliation(s)
- Matthew Rycenga
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA
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406
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Bhandari D, Kravchenko II, Lavrik NV, Sepaniak MJ. Nanotransfer Printing Using Plasma Etched Silicon Stamps and Mediated by in Situ Deposited Fluoropolymer. J Am Chem Soc 2011; 133:7722-4. [PMID: 21526774 DOI: 10.1021/ja201497a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Deepak Bhandari
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Ivan I. Kravchenko
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Nickolay V. Lavrik
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Michael J. Sepaniak
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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407
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Contreras-Cáceres R, Abalde-Cela S, Guardia-Girós P, Fernández-Barbero A, Pérez-Juste J, Alvarez-Puebla RA, Liz-Marzán LM. Multifunctional microgel magnetic/optical traps for SERS ultradetection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4520-4525. [PMID: 21438515 DOI: 10.1021/la200266e] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report on the fabrication of a SERS substrate comprising magnetic and silver particles encapsulated within a poly(N-isopropylacrylamide) (pNIPAM) thermoresponsive microgel. This colloidal substrate has the ability to adsorb analytes from solution while it is expanded (low temperature) and reversibly generate hot spots upon collapse (high temperature or drying). Additionally, the magnetic functionality permits concentration of the composite particles into small spatial regions, which can be exploited to decrease the amount of material per analysis while improving its SERS detection limit. Proof of concept for the sequestration of uncommon molecular systems is demonstrated through the first SERS analysis of pentachlorophenol (PCP), a chlorinated ubiquitous environmental pollutant.
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Affiliation(s)
- Rafael Contreras-Cáceres
- Departamento de Química Física, and Unidad Asociada CSIC-Universidade de Vigo, 36310, Vigo, Spain
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408
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Romo-Herrera JM, Alvarez-Puebla RA, Liz-Marzán LM. Controlled assembly of plasmonic colloidal nanoparticle clusters. NANOSCALE 2011; 3:1304-15. [PMID: 21229160 DOI: 10.1039/c0nr00804d] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Coupling of localized surface plasmon resonances results in singular effects at the void space between noble metal nanoparticles. However, implementation of practical applications based on plasmon coupling calls for the high yield production of metal nanoparticle clusters (dimers, trimers, tetramers, …) with small gaps. Therefore, controlled assembly using colloid chemistry methods is an emerging and promising field. We present a brief overview over the controlled assembly of plasmonic nanoparticle clusters by colloid chemistry methods, together with a description of their plasmonic properties and some applications, with an emphasis in sensing through surface-enhanced Raman scattering spectroscopy for bio-detection purposes. We point out the important role of separation methods to obtain colloidal clusters in high yield. A special encouragement to explore assembly of anisotropic building blocks is pursued.
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Affiliation(s)
- José M Romo-Herrera
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310, Vigo, Spain.
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409
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Margueritat J, Gehan H, Grand J, Lévi G, Aubard J, Félidj N, Bouhelier A, Colas-Des-Francs G, Markey L, Marco De Lucas C, Dereux A, Finot E. Influence of the number of nanoparticles on the enhancement properties of surface-enhanced Raman scattering active area: sensitivity versus repeatability. ACS NANO 2011; 5:1630-1638. [PMID: 21366249 DOI: 10.1021/nn103256t] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In the present work, the combination of chemical immobilization with electron beam lithography enables the production of sensitive and reproducible SERS-active areas composed of stochastic arrangements of gold nanoparticles. The number of nanoparticles was varied from 2 to 500. Thereby a systematic analysis of these SERS-active areas allows us to study SERS efficiency as a function of the number of nanoparticles. We found that the experimental parameters are critical, in particular the size of the SERS-active area must be comparable to the effective area of excitation to obtained reproducible SERS measurements. The sensitivity has also been studied by deducing the number of NPs that generate the enhancement. With this approach we demonstrates that the maximum enhancement, the best sensitivity, is obtained with the smallest number of nanoparticles that is resonant at a given excitation wavelength.
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Affiliation(s)
- Jérémie Margueritat
- Interfaces, Traitements, Organisations et Dynamique des Systèmes, Université Paris7-Denis Diderot, UMR 7086, Bâtiment Lavoisier, 15 rue Jean de Baïf, 75205 Paris, France.
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410
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Liu J, White I, DeVoe DL. Nanoparticle-functionalized porous polymer monolith detection elements for surface-enhanced Raman scattering. Anal Chem 2011; 83:2119-24. [PMID: 21322579 PMCID: PMC3056888 DOI: 10.1021/ac102932d] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The use of porous polymer monoliths functionalized with silver nanoparticles is introduced in this work for high-sensitivity surface-enhanced Raman scattering (SERS) detection. Preparation of the SERS detection elements is a simple process comprising the synthesis of a discrete polymer monolith section within a silica capillary, followed by physically trapping silver nanoparticle aggregates within the monolith matrix. A SERS detection limit of 220 fmol for Rhodamine 6G is demonstrated, with excellent signal stability over a 24 h period. The capability of the SERS-active monolith for label-free detection of biomolecules was demonstrated by measurements of bradykinin and cytochrome c. The SERS-active monoliths can be readily integrated into miniaturized micrototal-analysis systems for online and label-free detection for a variety of biosensing, bioanalytical, and biomedical applications.
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Affiliation(s)
- Jikun Liu
- Department of Mechanical Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Ian White
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA
| | - Don L. DeVoe
- Department of Mechanical Engineering, University of Maryland, College Park, MD, 20742, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA
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411
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Weber-Bargioni A, Schwartzberg A, Cornaglia M, Ismach A, Urban JJ, Pang Y, Gordon R, Bokor J, Salmeron MB, Ogletree DF, Ashby P, Cabrini S, Schuck PJ. Hyperspectral nanoscale imaging on dielectric substrates with coaxial optical antenna scan probes. NANO LETTERS 2011; 11:1201-1207. [PMID: 21261258 DOI: 10.1021/nl104163m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have demonstrated hyperspectral tip-enhanced Raman imaging on dielectric substrates using linearly polarized light and nanofabricated coaxial antenna tips. A full Raman spectrum was acquired at each pixel of a 256 by 256 pixel contact-mode atomic force microscope image of carbon nanotubes grown on a fused silica microscope coverslip, allowing D and G mode intensity and D-mode peak shifts to be measured with ∼20 nm spatial resolution. Tip enhancement was sufficient to acquire useful Raman spectra in 50-100 ms. Coaxial scan probes combine the efficiency and enhanced, ultralocalized optical fields of plasmonically coupled antennae with the superior topographical imaging properties of sharp metal tips. The yield of the coaxial tip fabrication process is close to 100%, and the tips are sufficiently durable to support hours of contact-mode force microscope imaging. Our coaxial probes avoid the limitations associated with the "gap-mode" imaging geometry used in most tip-enhanced Raman studies to date, where a sharp metal tip is held ∼1 nm above a metallic substrate with the sample located in the gap.
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Affiliation(s)
- Alexander Weber-Bargioni
- Molecular Foundry, Lawrence Berkeley National Laboratory , One Cyclotron Road, Berkeley, California 94720, United States.
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412
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Black KC, Liu Z, Messersmith PB. Catechol Redox Induced Formation of Metal Core-Polymer Shell Nanoparticles. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2011; 23:1130-1135. [PMID: 21666825 PMCID: PMC3109993 DOI: 10.1021/cm1024487] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A novel strategy was developed to synthesize polymer-coated metal nanoparticles (NPs) through reduction of metal cations with 3,4-dihydroxyphenylalanine (DOPA)-containing polyethylene glycol (PEG) polymers. Catechol redox chemistry was used to both synthesize metal NPs and simultaneously form a cross-linked shell of PEG polymers on their surfaces. DOPA reduced gold and silver cations into neutral metal atoms, producing reactive quinones that covalently cross-linked the PEG molecules around the surface of the NP. Importantly, these PEG-functionalized metal NPs were stable in physiological ionic strengths and under centrifugation, and hold broad appeal since they absorb and scatter light in aqueous solutions.
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Affiliation(s)
- Kvar C.L. Black
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois 60208
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208
| | - Zhongqiang Liu
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois 60208
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208
| | - Phillip B. Messersmith
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois 60208
- Materials Science and Engineering Department, Northwestern University, Evanston, Illinois 60208
- Chemical and Biological Engineering Department, Northwestern University, Evanston, Illinois 60208
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208
- Institute for Bionanotechnology in Medicine, Northwestern University, Evanston, Illinois 60208
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois 60208
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413
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Otter CA, Patty PJ, Williams MAK, Waterland MR, Telfer SG. Mechanically interlocked gold and silver nanoparticles using metallosupramolecular catenane chemistry. NANOSCALE 2011; 3:941-944. [PMID: 21264434 DOI: 10.1039/c0nr00801j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have employed the toolbox of metallosupramolecular chemistry to mechanically interlock gold and silver nanoparticles. A specifically designed PEGthiol-functionalized bis(phenanthroline)copper(I) complex acts to 'catenate' the nanoparticles. The interlocked assemblies were characterised by three complementary techniques: DLS, SERS and TEM.
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Affiliation(s)
- Carl A Otter
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
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414
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Kleinman SL, Ringe E, Valley N, Wustholz KL, Phillips E, Scheidt KA, Schatz GC, Van Duyne RP. Single-Molecule Surface-Enhanced Raman Spectroscopy of Crystal Violet Isotopologues: Theory and Experiment. J Am Chem Soc 2011; 133:4115-22. [DOI: 10.1021/ja110964d] [Citation(s) in RCA: 367] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Samuel L. Kleinman
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Emilie Ringe
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Nicholas Valley
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Kristin L. Wustholz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Eric Phillips
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Karl A. Scheidt
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - George C. Schatz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Richard P. Van Duyne
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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415
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Zhang R, Wang Z, Song C, Yang J, Li J, Sadaf A, Cui Y. Surface-Enhanced Fluorescence from Fluorophore-Assembled Monolayers by Using Ag@SiO2 Nanoparticles. Chemphyschem 2011; 12:992-8. [DOI: 10.1002/cphc.201000849] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Revised: 01/22/2011] [Indexed: 12/31/2022]
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416
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Tabakman SM, Chen Z, Casalongue HS, Wang H, Dai H. A new approach to solution-phase gold seeding for SERS substrates. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:499-505. [PMID: 21360809 PMCID: PMC3155739 DOI: 10.1002/smll.201001836] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Indexed: 05/19/2023]
Abstract
Surface-enhanced Raman scattering (SERS) vastly improves signal-to-noise ratios as compared to traditional Raman scattering, making sensitive assays based upon Raman scattering a reality. However, preparation of highly stable SERS-active gold substrates requires complicated and expensive methodologies and instrumentation. Here, a general and completely solution-phase, seed-based approach is introduced, which is capable of producing gold films for SERS applications on a variety of substrates, not requiring surface modification or functionalization. SERS enhancement factors of ≈10(7) were observed. Moreover, solution-phase gold film deposition on highly complex surfaces, such as protein-coated bioassays, is demonstrated for the first time. Protein bioassays coated with such SERS-active gold films are combined with bioconjugated single-walled carbon nanotube Raman labels, affording highly sensitive detection of the cancer biomarker, carcinoembryonic antigen in serum, with a limit of detection of ≈5 fM (1 pg mL(-1) ).
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Affiliation(s)
- Scott M. Tabakman
- Department of Chemistry, Stanford University. 380 Roth Way, Keck Building Room 125, Stanford, CA, 94305 USA
| | - Zhuo Chen
- Department of Chemistry, Stanford University. 380 Roth Way, Keck Building Room 125, Stanford, CA, 94305 USA
| | - Hernan Sanchez Casalongue
- Department of Chemistry, Stanford University. 380 Roth Way, Keck Building Room 125, Stanford, CA, 94305 USA
| | - Hailiang Wang
- Department of Chemistry, Stanford University. 380 Roth Way, Keck Building Room 125, Stanford, CA, 94305 USA
| | - Hongjie Dai
- Department of Chemistry, Stanford University. 380 Roth Way, Keck Building Room 125, Stanford, CA, 94305 USA
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417
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Larmour IA, Graham D. Surface enhanced optical spectroscopies for bioanalysis. Analyst 2011; 136:3831-53. [DOI: 10.1039/c1an15452d] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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418
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Zhang B, Xu P, Xie X, Wei H, Li Z, Mack NH, Han X, Xu H, Wang HL. Acid-directed synthesis of SERS-active hierarchical assemblies of silver nanostructures. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm02837a] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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419
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Tao CA, An Q, Zhu W, Yang H, Li W, Lin C, Xu D, Li G. Cucurbit[n]urils as a SERS hot-spot nanocontainer through bridging gold nanoparticles. Chem Commun (Camb) 2011; 47:9867-9. [DOI: 10.1039/c1cc12474a] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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420
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Kitahama Y, Tanaka Y, Itoh T, Ozaki Y. Power-law analysis of surface-plasmon-enhanced electromagnetic field dependence of blinking SERS of thiacyanine or thiacarbocyanine adsorbed on single silver nanoaggregates. Phys Chem Chem Phys 2011; 13:7439-48. [DOI: 10.1039/c0cp02802a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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421
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Hatab NA, Rouleau CM, Retterer ST, Eres G, Hatzinger PB, Gu B. An integrated portable Raman sensor with nanofabricated gold bowtie array substrates for energetics detection. Analyst 2011; 136:1697-702. [DOI: 10.1039/c0an00982b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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422
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Li R, Zhang H, Chen QW, Yan N, Wang H. Improved surface-enhanced Raman scattering on micro-scale Au hollow spheres: Synthesis and application in detecting tetracycline. Analyst 2011; 136:2527-32. [DOI: 10.1039/c1an15195a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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423
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Stoerzinger KA, Lin JY, Odom TW. Nanoparticle SERS substrates with 3D Raman-active volumes. Chem Sci 2011; 2:1435-1439. [PMID: 23997929 DOI: 10.1039/c1sc00125f] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This Perspective reviews a new class of surface-enhanced Raman scattering (SERS) nanoparticle substrates defined by their three-dimensional (3D) confinement of localized electromagnetic fields. First, we describe the critical design parameters and recent advances in nanofabrication to create reproducible nanoparticle assemblies for SERS. Next, we highlight a promising platform-gold nanopyramids-for testing how the local arrangement of particles in an assembly affects the overall SERS response. The dimensions and optical properties of the nanopyramids can be tuned easily, and their unique anisotropic shape allows them to be organized into different particle configurations with 3D Raman-active volumes. Because of their large hot-spot volumes, this unique class of nanoparticle substrates offers an attractive alternative for ultra-sensitive sensors and trace chemical analysis.
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Affiliation(s)
- Kelsey A Stoerzinger
- Department of Material Science and Engineering, Northwestern University, Evanston, IL, 60208-3113, USA
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424
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Ray PC, Yu H, Fu PP. Nanogold-based sensing of environmental toxins: excitement and challenges. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2011; 29:52-89. [PMID: 21424976 DOI: 10.1080/10590501.2011.551315] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
There have been tremendous advances in the past ten years on the development of various nanomaterials-based sensors for detection of environmental toxins. Nanogold is of special interest because of its unique shape- and size-dependent optical properties, hyper-quenching ability, super surface-enhanced Raman and dynamic light scattering, and surface-modifiability by small organic molecules and biomolecules. These unique optical properties of nanogold have been explored for ultra-sensitive detection, while its surface-modifiability has been explored for selectivity. In general, the nanogold-based sensors are highly selective and sensitive along with simple sample preparation and sensor design. In this review article, we intend to capture some of the recent advances in nanogold-based sensor development and mechanistic studies, especially for bacteria, heavy metals, and nitroaromatic compounds. Undoubtedly, these developments will generate a lot of excitement for environmental scientists and toxicologists as well as the general public.
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Affiliation(s)
- Paresh Chandra Ray
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA.
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425
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Fateixa S, Girão AV, Nogueira HIS, Trindade T. Polymer based silver nanocomposites as versatile solid film and aqueous emulsion SERS substrates. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm12444g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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426
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Label free sub-picomole level DNA detection with Ag nanoparticle decorated Au nanotip arrays as surface enhanced Raman spectroscopy platform. Biosens Bioelectron 2011; 26:2413-8. [DOI: 10.1016/j.bios.2010.10.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 10/11/2010] [Indexed: 11/23/2022]
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427
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Abstract
Significant advances have been made in the preparation and applications of surface-enhanced Raman scattering (SERS)-active materials for biomolecular analysis. Bright signals, photostability, and narrow spectral features of SERS-active materials offer attractive advantages for cytometric analyses. However, SERS cytometry is still in an early stage of development, and advances in both instrumentation and reagents will be necessary to realize its full potential. In this chapter, we discuss the challenges of expanding the numbers of fluorescent labels that can be measured in cytometry, and introduce SERS tags with extremely narrow spectral peaks as an approach to make more efficient use of the optical spectrum and increase the number of parameters in cytometry.
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Affiliation(s)
- John P Nolan
- La Jolla Bioengineering Institute, La Jolla, California, USA
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428
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dos Santos DP, Andrade GFS, Brolo AG, Temperini MLA. Fluctuations of the Stokes and anti-Stokes surface-enhanced resonance Raman scattering intensities in an electrochemical environment. Chem Commun (Camb) 2011; 47:7158-60. [DOI: 10.1039/c0cc05360k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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429
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Abalde-Cela S, Hermida-Ramón JM, Contreras-Carballada P, De Cola L, Guerrero-Martínez A, Alvarez-Puebla RA, Liz-Marzán LM. SERS Chiral Recognition and Quantification of Enantiomers through Cyclodextrin Supramolecular Complexation. Chemphyschem 2010; 12:1529-35. [DOI: 10.1002/cphc.201000800] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Indexed: 11/07/2022]
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430
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Kravets VG, Zoriniants G, Burrows CP, Schedin F, Casiraghi C, Klar P, Geim AK, Barnes WL, Grigorenko AN. Cascaded optical field enhancement in composite plasmonic nanostructures. PHYSICAL REVIEW LETTERS 2010; 105:246806. [PMID: 21231549 DOI: 10.1103/physrevlett.105.246806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 10/14/2010] [Indexed: 05/12/2023]
Abstract
We present composite plasmonic nanostructures designed to achieve cascaded enhancement of electromagnetic fields at optical frequencies. Our structures were made with the help of electron-beam lithography and comprise a set of metallic nanodisks placed one above another. The optical properties of reproducible arrays of these structures were studied by using scanning confocal Raman spectroscopy. We show that our composite nanostructures robustly demonstrate dramatic enhancement of the Raman signals when compared to those measured from constituent elements.
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Affiliation(s)
- V G Kravets
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
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431
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Hatab NA, Hsueh CH, Gaddis AL, Retterer ST, Li JH, Eres G, Zhang Z, Gu B. Free-standing optical gold bowtie nanoantenna with variable gap size for enhanced Raman spectroscopy. NANO LETTERS 2010; 10:4952-5. [PMID: 21090585 DOI: 10.1021/nl102963g] [Citation(s) in RCA: 223] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We describe plasmonic interactions in suspended gold bowtie nanoantenna leading to strong electromagnetic field (E) enhancements. Surface-enhanced Raman scattering (SERS) was used to demonstrate the performance of the nanoantenna. In addition to the well-known gap size dependence, up to 2 orders of magnitude additional enhancement is observed with elevated bowties. The overall behavior is described by a SERS enhancement factor exceeding 10(11) along with an anomalously weak power law dependence of E on the gap size in a range from 8 to 50 nm that is attributed to a plasmonic nanocavity effect occurring when the plasmonic interactions enter a strongly coupled regime.
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432
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Lu W, Singh AK, Khan SA, Senapati D, Yu H, Ray PC. Gold nano-popcorn-based targeted diagnosis, nanotherapy treatment, and in situ monitoring of photothermal therapy response of prostate cancer cells using surface-enhanced Raman spectroscopy. J Am Chem Soc 2010; 132:18103-14. [PMID: 21128627 DOI: 10.1021/ja104924b] [Citation(s) in RCA: 261] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Prostate cancer is the second leading cause of cancer-related death among the American male population, and the cost of treating prostate cancer patients is about $10 billion/year in the United States. Current treatments are mostly ineffective against advanced-stage prostate cancer and are often associated with severe side effects. Driven by these factors, we report a multifunctional, nanotechnology-driven, gold nano-popcorn-based surface-enhanced Raman scattering (SERS) assay for targeted sensing, nanotherapy treatment, and in situ monitoring of photothermal nanotherapy response during the therapy process. Our experimental data show that, in the presence of LNCaP human prostate cancer cells, multifunctional popcorn-shaped gold nanoparticles form several hot spots and provide a significant enhancement of the Raman signal intensity by several orders of magnitude (2.5 × 10(9)). As a result, it can recognize human prostate cancer cells at the 50-cells level. Our results indicate that the localized heating that occurs during near-infrared irradiation can cause irreparable cellular damage to the prostate cancer cells. Our in situ time-dependent results demonstrate for the first time that, by monitoring SERS intensity changes, one can monitor photothermal nanotherapy response during the therapy process. Possible mechanisms and operating principles of our SERS assay are discussed. Ultimately, this nanotechnology-driven assay could have enormous potential applications in rapid, on-site targeted sensing, nanotherapy treatment, and monitoring of the nanotherapy process, which are critical to providing effective treatment of cancer.
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Affiliation(s)
- Wentong Lu
- Department of Chemistry, Jackson State University, Jackson, Mississippi 39217-0510, USA
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433
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Dasary SSR, Senapati D, Singh AK, Anjaneyulu Y, Yu H, Ray PC. Highly sensitive and selective dynamic light-scattering assay for TNT detection using p-ATP attached gold nanoparticle. ACS APPLIED MATERIALS & INTERFACES 2010; 2:3455-60. [PMID: 21077646 PMCID: PMC3780396 DOI: 10.1021/am1005139] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
TNT is one of the most commonly used nitro aromatic explosives for landmines of military and terrorist activities. As a result, there is an urgent need for rapid and reliable methods for the detection of trace amount of TNT for screenings in airport, analysis of forensic samples, and environmental analysis. Driven by the need to detect trace amounts of TNT from environmental samples, this article demonstrates a label-free, highly selective, and ultrasensitive para-aminothiophenol (p-ATP) modified gold nanoparticle based dynamic light scattering (DLS) probe for TNT recognition in 100 pico molar (pM) level from ethanol:acetonitile mixture solution. Because of the formation of strong π-donor-acceptor interaction between TNT and p-ATP, para-aminothiophenol attached gold nanoparticles undergo aggregation in the presence of TNT, which changes the DLS intensity tremendously. A detailed mechanism for significant DLS intensity change has been discussed. Our experimental results show that TNT can be detected quickly and accurately without any dye tagging in 100 pM level with excellent discrimination against other nitro compounds.
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434
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Su YH, Tu SL, Tseng SW, Chang YC, Chang SH, Zhang WM. Influence of surface plasmon resonance on the emission intermittency of photoluminescence from gold nano-sea-urchins. NANOSCALE 2010; 2:2639-2646. [PMID: 20967388 DOI: 10.1039/c0nr00330a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The effect of surface plasmon resonance (SPR) on the blinking emission of photoluminescence from noble metal nanostructures still requires further investigation in quantum mechanics and limits their applications. We investigate one photon luminescent emission intermittency of noble metal nanostructures with differently sized sea-urchin-shaped nanoparticles, known as nano-sea-urchins (NSUs). The probability of the "on" process in one photon luminescent emission intermittency of NSUs increases due to the strong electric field of SPR. This mechanism is explained by the reaction potential threshold model we propose here. Furthermore, the ameliorated photoluminescence of NSUs is strong enough to excite waterweed bioluminescence and can act as an in vivo bio-light emitting device, which has potential applications in cytotoxicity, bio-imaging and bio-labeling.
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Affiliation(s)
- Yen Hsun Su
- Research Center for Applied Sciences, Academia Sinica, Taipei, 115, Taiwan.
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435
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Guarrotxena N, Liu B, Fabris L, Bazan GC. Antitags: nanostructured tools for developing SERS-based ELISA analogs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:4954-8. [PMID: 20812231 DOI: 10.1002/adma.201002369] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Affiliation(s)
- Nekane Guarrotxena
- Instituto de Ciencia y Tecnología de Polímeros, Consejo Superior de Investigaciones Científicas, Juan de la Cierva 3, Madrid 28006, Spain
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436
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Wustholz KL, Henry AI, McMahon JM, Freeman RG, Valley N, Piotti ME, Natan MJ, Schatz GC, Van Duyne RP. Structure-activity relationships in gold nanoparticle dimers and trimers for surface-enhanced Raman spectroscopy. J Am Chem Soc 2010; 132:10903-10. [PMID: 20681724 DOI: 10.1021/ja104174m] [Citation(s) in RCA: 426] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding the detailed relationship between nanoparticle structure and activity remains a significant challenge for the field of surface-enhanced Raman spectroscopy. To this end, the structural and optical properties of individual plasmonic nanoantennas comprised of Au nanoparticle assemblies that are coated with organic reporter molecules and encapsulated by a SiO(2) shell have been determined using correlated transmission electron microscopy (TEM), dark-field Rayleigh scattering microscopy, surface-enhanced Raman scattering (SERS) microscopy, and finite element method (FEM) calculations. The distribution of SERS enhancement factors (EFs) for a structurally and optically diverse set of nanoantennas is remarkably narrow. For a collection of 30 individual nanoantennas ranging from dimers to heptamers, the EFs vary by less than 2 orders of magnitude. Furthermore, the EFs for the hot-spot-containing nanoparticles are uncorrelated to aggregation state and localized surface plasmon resonance (LSPR) wavelength but are crucially dependent on the size of the interparticle gap. This study demonstrates that the creation of hot spots, where two particles are in subnanometer proximity or have coalesced to form crevices, is paramount to achieving maximum SERS enhancements.
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Affiliation(s)
- Kristin L Wustholz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA
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437
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Gehan H, Fillaud L, Chehimi MM, Aubard J, Hohenau A, Felidj N, Mangeney C. Thermo-induced electromagnetic coupling in gold/polymer hybrid plasmonic structures probed by surface-enhanced raman scattering. ACS NANO 2010; 4:6491-6500. [PMID: 21028846 DOI: 10.1021/nn101451q] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper describes a general stepwise strategy combining diazonium salt, surface-initiated atom transfer radical polymerization (SI-ATRP), and click chemistry for an efficient gold surface functionalization by poly(N-isopropylacrylamide) (PNIPAM) brushes and gold nanoparticle assemblies. We designed by this way a new plasmonic device made of gold nanoparticles separated from a gold film through a thermoresponsive polymer layer. This organic layer responds to temperature variations by conformational changes (with a characteristic temperature called the lower critical solution temperature, LCST) and is therefore able to vary the distance between the gold nanoparticles and the gold film. The optical properties of these stimulable substrates were probed by surface-enhanced raman scattering (SERS) using methylene blue (MB) as a molecular probe. We show that an increase of the external temperature reversibly induces a significant enhancement of the MB SERS signal. This was attributed to a stronger interaction between the gold nanoparticles and the gold substrate. The temperature-responsive plasmonic devices developed in this paper thus provide a dynamic SERS platform, with thermally switchable electromagnetic coupling between the gold nanoparticles and the gold surface.
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Affiliation(s)
- Hélène Gehan
- ITODYS, Université Paris Diderot-Paris 7 (UMR CNRS 7086), 15 rue Jean de Baïf, 75013 Paris, France
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438
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Guffey MJ, Scherer NF. All-optical patterning of Au nanoparticles on surfaces using optical traps. NANO LETTERS 2010; 10:4302-8. [PMID: 20925400 DOI: 10.1021/nl904167t] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The fabrication of nanoscale devices would be greatly enhanced by "nanomanipulators" that can position single and few objects rapidly with nanometer precision and without mechanical damage. Here, we demonstrate the feasibility and precision of an optical laser tweezer, or optical trap, approach to place single gold (Au) nanoparticles on surfaces with high precision (approximately 100 nm standard deviation). The error in the deposition process is rather small but is determined to be larger than the thermal fluctuations of single nanoparticles within the optical trap. Furthermore, areas of tens of square micrometers could be patterned in a matter of minutes. Since the method does not rely on lithography, scanning probes or a specialized surface, it is versatile and compatible with a variety of systems. We discuss active feedback methods to improve positioning accuracy and the potential for multiplexing and automation.
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Affiliation(s)
- Mason J Guffey
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
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439
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Wark AW, Stokes RJ, Darby SB, Smith WE, Graham D. Dynamic Imaging Analysis of SERS-Active Nanoparticle Clusters in Suspension. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2010; 114:18115-18120. [PMID: 23710264 PMCID: PMC3660949 DOI: 10.1021/jp107559x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 09/22/2010] [Indexed: 05/30/2023]
Abstract
A novel wide-field approach for the real-time Surface Enhanced Raman Scattering (SERS) imaging of multiple silver nanoparticle clusters suspended in solution is described. This method enables direct correlation of the SERS activity of a single nanoparticle aggregate and its size through measurement of the cluster diffusion coefficient and can also be performed in a high-throughput basis. As a first demonstration, we investigate the salt-induced aggregation of silver nanoparticles in the presence of a reporter tag molecule, which has a high affinity for the nanoparticle surface. In addition to tracking individual particles, direct comparison of Rayleigh and SERS videos of the same colloid solution enabled measurement of the fraction of individual clusters that are SERS active and the dependence of this value on the relative concentration of the tag molecule. Furthermore, given the ability to also rapidly profile any nonuniformity in particle size distributions, we expect this approach will not only provide a new tool for the fundamental understanding of SERS but also significantly contribute to the development of an array of emerging nanoparticle-enhanced biomolecule and imaging detection platforms.
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Affiliation(s)
- Alastair W. Wark
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, U.K., G1 1XL
| | - Robert J. Stokes
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, U.K., G1 1XL
| | - Steven B. Darby
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, U.K., G1 1XL
| | - W. Ewen Smith
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, U.K., G1 1XL
| | - Duncan Graham
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, U.K., G1 1XL
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440
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Lee SY, Hung L, Lang GS, Cornett JE, Mayergoyz ID, Rabin O. Dispersion in the SERS enhancement with silver nanocube dimers. ACS NANO 2010; 4:5763-72. [PMID: 20929243 DOI: 10.1021/nn101484a] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The SERS phenomenon was studied using a large set of silver nanocube dimers programmed to self-assemble in preset locations of a patterned substrate. This SERS substrate made it possible to demonstrate the dependence of the SERS enhancement on the geometry of the silver nanocube dimers and to quantify the dispersion in the SERS enhancement obtained in an ensemble of dimers. In addition to the effects of the gap distance of the dimer and the orientation of the dimer axis relative to the laser polarization on SERS enhancement, the data reveal an interesting dependence of the site-to-site variations of the enhancement on the relative orientation of the nanocubes in the dimer. We observed the highest heterogeneity in the SERS signal intensity with face-to-face dimers and a more robust SERS enhancement with face-to-edge dimers. Numerical calculations indicate that the plasmon resonance frequencies of face-to-face dimers shift considerably with small changes in gap distance. The resonance frequency shifts make it less likely for many of the dimers to satisfy the matching condition between the photon frequencies and the plasmon resonance frequency, offering an explanation for the large site-to-site variations in SERS signal intensity. These results indicate that plasmonic nanostructure designs for SERS substrates for real-world applications should be selected not only to maximize the signal enhancement potential but also to minimize the heterogeneity of the substrate with respect to signal enhancement. The latter criterion poses new challenges to experimentalists and theorists alike.
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Affiliation(s)
- Seung Yong Lee
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States, USA
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441
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Meyer KA, Polemi A, Shuford KL, Whitten WB, Shaw RW. Surface coating effects on the assembly of gold nanospheres. NANOTECHNOLOGY 2010; 21:415701. [PMID: 20834119 DOI: 10.1088/0957-4484/21/41/415701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Optical spectra and atomic force microscopy (AFM) images of individually selected spheres and mechanically assembled silica-coated gold nanosphere pairs were recorded. The shell served as a means of rigid control of the minimum spacing between the metal cores. The spectra of the assembled spheres were simulated using classical electrodynamics. The observed spectra resulted in superior characterization of the particle assembly geometry, relative to the AFM data. Experimental investigations regarding less-rigid polyvinylpyrrolidone (PVP) sphere coatings were also performed and some comparisons were made.
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Affiliation(s)
- Kent A Meyer
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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442
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Chen LL, Jiang L, Wang YL, Qian J, He S. Multilayered polyelectrolyte-coated gold nanorods as multifunctional optical contrast agents for cancer cell imaging. J Zhejiang Univ Sci B 2010; 11:417-22. [PMID: 20506571 DOI: 10.1631/jzus.b0910731] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We report the application of multilayered polyelectrolyte-coated gold nanorods (GNRs) as multifunctional optical contrast agents for cancer cell imaging. The surface modification of GNRs improves their chemical stability and facilitates them to be taken up by cancer cells through electrostatic interaction. The unique longitudinal surface plasmon resonance property of GNRs makes them suitable as both "scattering contrast agents" and "Raman contrast agents". In our experiments, the staining of GNRs in cells was further confirmed by dark field microscopy and Raman microscopy. Our experiment results indicated that GNRs have great potential as multifunctional "optical contrast agents" for future in vivo animal imaging.
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Affiliation(s)
- Li-li Chen
- Centre for Optical and Electromagnetic Research, State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310058, China
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443
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Luchowski R, Calander N, Shtoyko T, Apicella E, Borejdo J, Gryczynski Z, Gryczynski I. Plasmonic platforms of self-assembled silver nanostructures in application to fluorescence. JOURNAL OF NANOPHOTONICS 2010; 4:043516. [PMID: 21403765 PMCID: PMC3053531 DOI: 10.1117/1.3500463] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fluorescence intensity changes were investigated theoretically and experimentally using self-assembled colloidal structures on silver semitransparent mirrors. Using a simplified quasi-static model and finite element method, we demonstrate that near-field interactions of metallic nanostructures with a continuous metallic surface create conditions that produce enormously enhanced surface plasmon resonances. The results were used to explain the observed enhancements and determine the optimal conditions for the experiment. The theoretical parts of the studies are supported with reports on detailed emission intensity changes which provided multiple fluorescence hot spots with 2-3 orders of enhancements. We study two kinds of the fluorophores: dye molecules and fluorescent nanospheres characterized with similar spectral emission regions. Using a lifetime-resolved fluorescence/reflection confocal microscopy technique, we find that the largest rate for enhancement (~1000-fold) comes from localized areas of silver nanostructures.
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Affiliation(s)
- Rafal Luchowski
- University of North Texas Health Science Center, Department of Molecular Biology and Immunology, Center for Commercialization of Fluorescence Technologies, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
- Maria Curie-Sklodowska University, Department of Biophysics, 20-031 Lublin, Poland
| | - Nils Calander
- University of North Texas Health Science Center, Department of Molecular Biology and Immunology, Center for Commercialization of Fluorescence Technologies, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
- Macquarie University, Department of Physics, NSW 2109, Sydney, Australia
| | | | - Elisa Apicella
- University of North Texas Health Science Center, Department of Molecular Biology and Immunology, Center for Commercialization of Fluorescence Technologies, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
| | - Julian Borejdo
- University of North Texas Health Science Center, Department of Molecular Biology and Immunology, Center for Commercialization of Fluorescence Technologies, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
| | - Zygmunt Gryczynski
- University of North Texas Health Science Center, Department of Molecular Biology and Immunology, Center for Commercialization of Fluorescence Technologies, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
- University of North Texas Health Science Center, Department of Cell Biology and Anatomy, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
| | - Ignacy Gryczynski
- University of North Texas Health Science Center, Department of Molecular Biology and Immunology, Center for Commercialization of Fluorescence Technologies, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
- University of North Texas Health Science Center, Department of Cell Biology and Anatomy, 3500 Camp Bowie Blvd., Fort Worth, TX 76107
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444
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Stranahan SM, Willets KA. Super-resolution optical imaging of single-molecule SERS hot spots. NANO LETTERS 2010; 10:3777-84. [PMID: 20718441 DOI: 10.1021/nl102559d] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present the first super-resolution optical images of single-molecule surface-enhanced Raman scattering (SM-SERS) hot spots, using super-resolution imaging as a powerful new tool for understanding the interaction between single molecules and nanoparticle hot spots. Using point spread function fitting, we map the centroid position of SM-SERS with +/-10 nm resolution, revealing a spatial relationship between the SM-SERS centroid position and the highest SERS intensity. We are also able to measure the unique position of the SM-SERS centroid relative to the centroid associated with nanoparticle photoluminescence, which allows us to speculate on the presence of multiple hot spots within a single diffraction-limited spot. These measurements allow us to follow dynamic movement of the SM-SERS centroid position over time as it samples different locations in space and explores regions larger than the expected size of a SM-SERS hot spot. We have proposed that the movement of the SERS centroid is due to diffusion of a single molecule on the surface of the nanoparticle, which leads to changes in coupling between the scattering dipole and the optical near field of the nanoparticle.
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Affiliation(s)
- Sarah M Stranahan
- Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712, USA
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445
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Hu M, Ou FS, Wu W, Naumov I, Li X, Bratkovsky AM, Williams RS, Li Z. Gold Nanofingers for Molecule Trapping and Detection. J Am Chem Soc 2010; 132:12820-2. [DOI: 10.1021/ja105248h] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Min Hu
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - Fung Suong Ou
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - Wei Wu
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - Ivan Naumov
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - Xuema Li
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - Alexander M. Bratkovsky
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - R. Stanley Williams
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
| | - Zhiyong Li
- Information & Quantum Systems Laboratory, Hewlett-Packard Laboratories, 1501 Page Mill Road, MS1123, Palo Alto, California 94304
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446
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447
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Theiss J, Pavaskar P, Echternach PM, Muller RE, Cronin SB. Plasmonic nanoparticle arrays with nanometer separation for high-performance SERS substrates. NANO LETTERS 2010; 10:2749-54. [PMID: 20698586 DOI: 10.1021/nl904170g] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We demonstrate a method for fabricating arrays of plasmonic nanoparticles with separations on the order of 1 nm using an angle evaporation technique. Samples fabricated on thin SiN membranes are imaged with high-resolution transmission electron microscopy (HRTEM) to resolve the small separations achieved between nanoparticles. When irradiated with laser light, these nearly touching metal nanoparticles produce extremely high electric field intensities, which result in surface-enhanced Raman spectroscopy (SERS) signals. We quantify these enhancements by depositing a p-aminothiophenol dye molecule on the nanoparticle arrays and spatially mapping their Raman intensities using confocal micro-Raman spectroscopy. Our results show significant enhancement when the incident laser is polarized parallel to the axis of the nanoparticle pairs, whereas no enhancement is observed for the perpendicular polarization. These results demonstrate proof-of-principle of this fabrication technique. Finite difference time domain simulations based on HRTEM images predict an electric field intensity enhancement of 82400 at the center of the nanoparticle pair and an electromagnetic SERS enhancement factor of 10(9)-10(10).
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Affiliation(s)
- Jesse Theiss
- Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA
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448
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Chen T, Wang H, Chen G, Wang Y, Feng Y, Teo WS, Wu T, Chen H. Hotspot-induced transformation of surface-enhanced Raman scattering fingerprints. ACS NANO 2010; 4:3087-3094. [PMID: 20509669 DOI: 10.1021/nn100269v] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The most studied effect of surface-enhanced Raman scattering (SERS) hotspots is the enormous Raman enhancement of the analytes therein. A less known effect, though, is that the formation of hotspots may cause the trapped analytes to change molecular orientation, which in turn leads to pronounced changes in SERS fingerprints. Here, we demonstrate this effect by creating and characterizing hotspots in colloidal solutions. Anisotropically functionalized Au nanorods were synthesized, whereby the sides were specifically encapsulated by polystyrene-block-poly(acrylic acid), leaving the ends unencapsulated and functionalized by a SERS analyte, 4-mercaptobenzoic acid. Upon salt treatment, these nanorods assemble into linear chains, forming hotspots that incorporate the SERS analyte. Enormous SERS enhancement was observed, particularly for some weak/inactive SERS modes that were not present in the original spectrum before the hotspots formation. Detailed spectral analysis showed that the variations of the SERS fingerprint were consistent with the reorientation of analyte molecules from nearly upright to parallel/tilted conformation on the Au surface. We propose that the aggregation of Au nanorods exerts physical stress on the analytes in the hotspots, causing the molecular reorientation. Such a hotspot-induced variation of SERS fingerprints was also observed in several other systems using different analytes.
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Affiliation(s)
- Tao Chen
- Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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449
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Xu P, Mack NH, Jeon SH, Doorn SK, Han X, Wang HL. Facile fabrication of homogeneous 3D silver nanostructures on gold-supported polyaniline membranes as promising SERS substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8882-8886. [PMID: 20158171 DOI: 10.1021/la904617p] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report a facile synthesis of large-area homogeneous three-dimensional (3D) Ag nanostructures on Au-supported polyaniline (PANI) membranes through a direct chemical reduction of metal ions by PANI. The citric acid absorbed on the Au nuclei that are prefabricated on PANI membranes directs Ag nanoaprticles (AgNPs) to self-assemble into 3D Ag nanosheet structures. The fabricated hybrid metal nanostructures display uniform surface-enhanced Raman scattering (SERS) responses throughout the whole surface area, with an average enhancement factor of 10(6)-10(7). The nanocavities formed by the stereotypical stacking of these Ag nanosheets and the junctions and gaps between two neighboring AgNPs are believed to be responsible for the strong SERS response upon plasmon absorption. These homogeneous metal nanostructure decorated PANI membranes can be used as highly efficient SERS substrates for sensitive detection of chemical and biological analytes.
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Affiliation(s)
- Ping Xu
- Physical Chemistry and Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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450
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Stoerzinger KA, Hasan W, Lin JY, Robles A, Odom TW. Gold Nanopyramids Assembled into High-Order Stacks Exhibit Increased SERS Response. J Phys Chem Lett 2010; 1:1046-1050. [PMID: 21666758 PMCID: PMC3110716 DOI: 10.1021/jz100095b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This Letter describes how gold pyramidal nanoshells (nanopyramids) can be assembled into low- and high-order structures by varying the rate of solvent evaporation and surface wettability. Single-particle and individual-cluster dark field scattering spectra on isolated, dimers and trimers of nanopyramids were compared. We found that the short wavelength resonances blue-shifted as the particles assembled; the magnitude of this shift was greater for high-order structures. To test which assembled architecture supported a larger Raman-active volume, we compared their surface enhanced Raman scattering (SERS) response of the resonant Raman molecule methylene blue (λ(ex) = 633 nm). We discovered that high-order structures exhibited more Raman scattering compared to low-order assemblies. Finite-difference time-domain modeling of nanopyramid assemblies revealed that the highest electromagnetic field intensities were localized between adjacent particle faces, a result that was consistent with the SERS observations. Thus, the local spatial arrangement of the same number of nanoparticles in assembled clusters is an important design parameter for optimizing nanoparticle-based SERS sensors.
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Affiliation(s)
- Kelsey A. Stoerzinger
- Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
| | - Warefta Hasan
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
| | - Julia Y. Lin
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
| | - Alex Robles
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
| | - Teri W. Odom
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
- Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
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