251
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MALYNYCH S, CHUMANOV G. Narrow plasmon mode in 2D arrays of silver nanoparticles self-assembled on thin silver films. J Microsc 2008; 229:567-74. [DOI: 10.1111/j.1365-2818.2008.01945.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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252
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Alexander TA. Development of Methodology Based on Commercialized SERS-Active Substrates for Rapid Discrimination of Poxviridae Virions. Anal Chem 2008; 80:2817-25. [DOI: 10.1021/ac702464w] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Troy A. Alexander
- U.S. Army Research Laboratory Sensors and Electron Devices Directorate, Photonics Integration BranchRadiometric Sensor Development and Applications Team, AMSRD-ARL-SE-EE, 2800 Powder Mill Road, Adelphi, Maryland 20783
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253
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Sun Y, Wang L, Sun L, Guo C, Yang T, Liu Z, Xu F, Li Z. Fabrication, characterization, and application in surface-enhanced Raman spectrum of assembled type-I collagen-silver nanoparticle multilayered films. J Chem Phys 2008; 128:074704. [DOI: 10.1063/1.2832322] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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254
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Surface-Enhanced Raman Scattering of Benzenethiol Adsorbed on Silver-Exchanged Copper Powders. B KOREAN CHEM SOC 2008. [DOI: 10.5012/bkcs.2008.29.2.445] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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255
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Siwach OP, Sen P. Fluorescence properties of Ag nanoparticles in water. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2008; 69:659-63. [PMID: 17573235 DOI: 10.1016/j.saa.2007.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 05/05/2007] [Accepted: 05/08/2007] [Indexed: 05/15/2023]
Abstract
Ag nanoparticles in water phase have been synthesized employing the electro-exploding wire technique. A surface plasmon peak is observed at 400nm, characteristic of the Ag nanoparticles. A fluorescence emission peak is recorded at 300nm for excitation wavelengths in two different ranges 215-230 and 255-280nm. The position of the fluorescence peak remains fixed, irrespective of the excitation wavelength employed. These are assigned to electronic transition from different higher excited states to d levels of the Ag nanoparticles. In concomitant with these, there are two resonant absorptions at 5.76 and 4.59eV as evident from the fluorescence excitation spectra.
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Affiliation(s)
- Om Parkash Siwach
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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256
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Easy deposition of Ag onto polystyrene beads for developing surface-enhanced-Raman-scattering-based molecular sensors. J Colloid Interface Sci 2008; 318:195-201. [DOI: 10.1016/j.jcis.2007.09.025] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Revised: 09/11/2007] [Accepted: 09/12/2007] [Indexed: 11/18/2022]
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257
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Moussodia RO, Balan L, Schneider R. Synthesis and characterization of water-soluble ZnO quantum dots prepared through PEG-siloxane coating. NEW J CHEM 2008. [DOI: 10.1039/b719642c] [Citation(s) in RCA: 36] [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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258
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Šloufová I, Šišková K, Vlčková B, Štěpánek J. SERS-activating effect of chlorides on borate-stabilized silver nanoparticles: formation of new reduced adsorption sites and induced nanoparticle fusion. Phys Chem Chem Phys 2008; 10:2233-42. [DOI: 10.1039/b718178g] [Citation(s) in RCA: 27] [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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259
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Qian XM, Nie SM. Single-molecule and single-nanoparticle SERS: from fundamental mechanisms to biomedical applications. Chem Soc Rev 2008; 37:912-20. [DOI: 10.1039/b708839f] [Citation(s) in RCA: 931] [Impact Index Per Article: 58.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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260
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Porter MD, Lipert RJ, Siperko LM, Wang G, Narayanan R. SERS as a bioassay platform: fundamentals, design, and applications. Chem Soc Rev 2008; 37:1001-11. [DOI: 10.1039/b708461g] [Citation(s) in RCA: 477] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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261
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Vo-Dinh T. Nanobiosensing Using Plasmonic Nanoprobes. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2008; 14:198-205. [PMID: 24839386 PMCID: PMC4022293 DOI: 10.1109/jstqe.2007.914738] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper provides an overview of the development and applications of plasmonics-active nanoprobes in biomedical diagnostics. Specific examples of detection techniques using surface-enhanced Raman scattering are presented to illustrate the usefulness and potential of the plasmonics nanoprobes for gene detection and nanobiosensing. The detection of specific target deoxyribonucleic acids sequences using a novel "molecular sentinel" nanoprobe method is presented and discussed in detail.
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Affiliation(s)
- Tuan Vo-Dinh
- Fitzpatrick Institute for Photonics, Departments of Biomedical Engineering and Chemistry, Duke University, Durham NC 27708 USA
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262
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Lutz B, Dentinger C, Sun L, Nguyen L, Zhang J, Chmura A, Allen A, Chan S, Knudsen B. Raman nanoparticle probes for antibody-based protein detection in tissues. J Histochem Cytochem 2007; 56:371-9. [PMID: 18071064 DOI: 10.1369/jhc.7a7313.2007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surface-enhanced Raman scattering (SERS) nanoparticles are emerging as a new approach for optical detection of biomolecules. In a model assay in formalin-fixed paraffin-embedded (FFPE) prostate tissue sections, we detect prostate-specific antigen (PSA) using antibody (Ab) conjugated to composite organic-inorganic nanoparticles (COINs), and we use identical staining protocols to compare COIN-Ab and Alexa-Ab conjugates in adjacent tissue sections. Spectral analysis illustrates the fundamental difference between fluorescence and Raman signatures and accurately extracts COIN probe signals from background autofluorescence. Probe signals are used to generate images of PSA expression on the tissue, and quality measures are presented to characterize the performance of the COIN assay in comparison to Alexa. Staining accuracy (ability to correctly identify PSA expression in epithelial cells) is somewhat less for COIN than Alexa, which is attributed to an elevated false negative rate of the COIN. However, COIN provided signal intensities comparable to Alexa, and good intra-, inter-, and lot-to-lot consistencies. Overall, COIN and Alexa detection reagents possess similar performance with FFPE tissues, supporting the further development of Raman probes for this application. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.
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Affiliation(s)
- Barry Lutz
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, M5-A864, 1212 Aloha St., Seattle, WA 95054, USA
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263
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Carbó-Argibay E, Rodríguez-González B, Pacifico J, Pastoriza-Santos I, Pérez-Juste J, Liz-Marzán L. Chemical Sharpening of Gold Nanorods: The Rod-to-Octahedron Transition. Angew Chem Int Ed Engl 2007; 46:8983-7. [DOI: 10.1002/anie.200703259] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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264
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265
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Dieringer JA, Lettan RB, Scheidt KA, Van Duyne RP. A Frequency Domain Existence Proof of Single-Molecule Surface-Enhanced Raman Spectroscopy. J Am Chem Soc 2007; 129:16249-56. [DOI: 10.1021/ja077243c] [Citation(s) in RCA: 456] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jon A. Dieringer
- Northwestern University, Department of Chemistry, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Robert B. Lettan
- Northwestern University, Department of Chemistry, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Karl A. Scheidt
- Northwestern University, Department of Chemistry, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Richard P. Van Duyne
- Northwestern University, Department of Chemistry, 2145 Sheridan Road, Evanston, Illinois 60208
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266
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Liu YC, Yu CC, Yang KH, Chen JS. Optimally electrochemically roughened silver substrates prepared in gold complexes-containing solutions for trace molecules detection. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2007.08.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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267
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268
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Abu-Hatab NA, John JF, Oran JM, Sepaniak MJ. Multiplexed microfluidic surface-enhanced Raman spectroscopy. APPLIED SPECTROSCOPY 2007; 61:1116-22. [PMID: 17958963 DOI: 10.1366/000370207782217842] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Over the past few decades, surface-enhanced Raman spectroscopy (SERS) has garnered respect as an analytical technique with significant chemical and biological applications. SERS is important for the life sciences because it can provide trace level detection, a high level of structural information, and enhanced chemical detection. However, creating and successfully implementing a sensitive, reproducible, and robust SERS active substrate continues to be a challenging task. Herein, we report a novel method for SERS that is based upon using multiplexed microfluidics (MMFs) in a polydimethylsiloxane platform to perform parallel, high throughput, and sensitive detection/identification of single or various analytes under easily manipulated conditions. A facile passive pumping method is used to deliver Ag colloids and analytes into the channels where SERS measurements are done under nondestructive flowing conditions. With this approach, SERS signal reproducibility is found to be better than 7%. Utilizing a very high numerical aperture microscope objective with a confocal-based Raman spectrometer, high sensitivity is achieved. Moreover, the long working distance of this objective coupled with an appreciable channel depth obviates normal alignment issues expected with translational multiplexing. Rapid evaluation of the effects of anion activators and the type of colloid employed on SERS performance are used to demonstrate the efficiency and applicability of the MMF approach. SERS spectra of various pesticides were also obtained. Calibration curves of crystal violet (non-resonant enhanced) and Mitoxantrone (resonant enhanced) were generated, and the major SERS bands of these analytes were observable down to concentrations in the low nM and sub-pM ranges, respectively. While conventional random morphology colloids were used in most of these studies, unique cubic nanoparticles of silver were synthesized with different sizes and studied using visible wavelength optical extinction spectrometry, scanning electron microscopy, and the MMF-SERS approach.
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Affiliation(s)
- Nahla A Abu-Hatab
- University of Tennessee-Knoxville, Department of Chemistry, 552 Buehler Hall, Knoxville, Tennessee 37996-1600, USA
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269
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Tiwari VS, Oleg T, Darbha GK, Hardy W, Singh J, Ray PC. Non-resonance SERS effects of silver colloids with different shapes. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.07.106] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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270
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Emory SR, Jensen RA, Wenda T, Han M, Nie S. Re-examining the origins of spectral blinking in single-molecule and single-nanoparticle SERS. Faraday Discuss 2007; 132:249-59; discussion 309-19. [PMID: 16833120 DOI: 10.1039/b509223j] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Single metal nanoparticles and nanoaggregates are known to emit intense bursts of surface-enhanced Raman scattering (SERS) in an intermittent on and off fashion. The characteristic "blinking" timescales range from milliseconds to seconds. Here we report detailed temperature dependence (both heating and cooling) and light-intensity studies to further examine the origins of this intriguing phenomenon. The results indicate that blinking SERS contains both a thermo-activated component and a light-induced component. Several lines of evidence suggest that the observed fluctuations are caused by thermally activated diffusion of individual molecules on the particle surface, coupled with photo-induced electron transfer and structural relaxation of surface active sites or atomic-scale roughness features.
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Affiliation(s)
- Steven R Emory
- Department of Chemistry, Western Washington University, Bellingham WA 98225, USA.
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271
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Kim K, Lee HS. Effect of Ag and Au nanoparticles on the SERS of 4-aminobenzenethiol assembled on powdered copper. J Phys Chem B 2007; 109:18929-34. [PMID: 16853437 DOI: 10.1021/jp052665z] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Raman scattering measurements were conducted for 4-aminobenzenethiol (4-ABT) assembled on powdered copper substrates. Initially, very weak Raman peaks were detected, but upon attaching Ag nanoparticles probably via NH2 groups onto 4-ABT/Cu, distinct Raman spectra were observed. Considering the fact that no Raman peak was identified when Ag nanoparticles were adsorbed on 4-aminophenyl-derivatized silane monolayers assembled on silica powders, the Raman spectra observed for Ag@4-ABT/Cu should be surface-enhanced Raman scattering (SERS) spectra, occurring by an electromagnetic coupling of the localized surface plasmon of Ag nanoparticles with the surface plasmon polariton of Cu powders. The extra enhancement factor attainable by the attachment of a single Ag nanoparticle is estimated to be as large as 1.4 x 10(5) in the case when 632.8-nm radiation is used as the excitation source. When Au nanoparticles were attached onto 4-ABT/Cu, at least an order of magnitude weaker Raman spectra were obtained at all excitation wavelengths, however, indicating that the Au-to-Cu coupling should be far less effective than the Ag-to-Cu coupling for the induction of SERS.
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Affiliation(s)
- Kwan Kim
- Laboratory of Intelligent Interfaces, School of Chemistry, Seoul National University, Seoul 151-742, Korea.
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272
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Lombardi JR, Birke RL. Time-dependent picture of the charge-transfer contributions to surface enhanced Raman spectroscopy. J Chem Phys 2007; 126:244709. [PMID: 17614579 DOI: 10.1063/1.2748386] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We reexamine the Herzberg-Teller theory of charge-transfer contributions to the theory of surface enhanced Raman scattering (SERS). In previous work, the Kramers-Heisenberg-Dirac framework was utilized to explain many of the observed features in SERS. However, recent experimental and theoretical developments suggest that we revise the theory to take advantage of the time-dependent picture of Raman scattering. Results are obtained for molecular adsorption on nanoparticles in both the strong confinement limit and the weak confinement limit. We show that the Herzberg-Teller contributions to the charge-transfer effect in SERS display a resonance at the molecule-to-metal or metal-to-molecule transition while retaining the selection rules associated with normal Raman spectroscopy (i.e., harmonic oscillator, as opposed to Franck-Condon overlaps). The charge-transfer contribution to the enhancement factor scales as Gamma(-4), where Gamma is the homogeneous linewidth of the charge-transfer transition, and thus is extremely sensitive to the magnitude of this parameter. We show that the Herzberg-Teller coupling term may be associated with the polaron-coupling constant of the surface phonon-electron interaction. A time-dependent expression for the Raman amplitude is developed, and we discuss the implications of these results for both metal and semiconductor nanoparticle surfaces.
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Affiliation(s)
- John R Lombardi
- Department of Chemistry, The City College of New York, New York, New York 10031, USA
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273
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Wang Z, Rothberg LJ. Origins of blinking in single-molecule Raman spectroscopy. J Phys Chem B 2007; 109:3387-91. [PMID: 16851369 DOI: 10.1021/jp0460947] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We observe spectral and intensity fluctuations in Raman scattering from single molecules of 4-mercaptopyridine (4-Mpy) adsorbed on textured silver surfaces. We present evidence that the root cause of these fluctuations is thermal. Analysis of the spectra shows that in some cases the spectral changes are associated with molecular reorientation and in others with chemical reactions of the 4-Mpy. Analogous surfaces fully covered with 4-Mpy exhibit similar behavior, indicating that monolayer Raman spectra are dominated by a few molecules at most.
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Affiliation(s)
- Zhenjia Wang
- Department of Chemistry, University of Rochester, Rochester, New York 14627, USA
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274
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Pergolese B, Muniz-Miranda M, Bigotto A. Surface enhanced Raman scattering investigation of the halide anion effect on the adsorption of 1,2,3-triazole on silver and gold colloidal nanoparticles. J Phys Chem B 2007; 109:9665-71. [PMID: 16852164 DOI: 10.1021/jp050155z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The halide anion effect on the adsorption of 1,2,3-triazole on Ag and Au colloidal nanoparticles has been investigated by means of surface enhanced Raman scattering (SERS), UV-visible absorption spectroscopy, and scanning electron microscopy. To interpret the SERS spectra, the vibrational spectra of 1,2,3-triazole were assigned with the help of density functional theoretical (DFT) calculations of the two tautomers of 1,2,3-triazole, both free and bound to Ag and Au adatoms. Upon addition of halide anions, both tautomers interact with the Ag surface through one nitrogen atom. Analogous behavior is observed in the case of basified Au colloids, whereas at the usual pH of these hydrosols (approximately 6) the adsorption of 1,2,3-triazole is the same of that observed in halide-free colloids.
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Affiliation(s)
- Barbara Pergolese
- Department of Chemical Sciences, University of Trieste,Via L. Giorgieri 1, I-34127 Trieste, Italy.
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275
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Alexander TA, Le DM. Characterization of a commercialized SERS-active substrate and its application to the identification of intact Bacillus endospores. APPLIED OPTICS 2007; 46:3878-90. [PMID: 17538686 DOI: 10.1364/ao.46.003878] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Surface-enhanced-Raman-spectroscopy (SERS) can be made an attractive approach for the identification of Raman-active compounds and biological materials (i.e., toxins, viruses, or intact bacterial cells or spores) through development of reproducible, spatially uniform SERS-active substrates. Recently, reproducible (from substrate to substrate), spatially homogeneous (over large areas) SERS-active substrates have been commercialized and are now available in the marketplace. Scanning electron microscopy and high-resolution, tapping-mode atomic force microscopy have been used to analyze these novel plasmonic surfaces for topographical consistency. Additionally, we have assessed, by wavelength-tunable microreflectance spectrometry, the spatial distribution of the localized surface plasmon resonance (LSPR) across a single substrate surface as well as the LSPR lambda(MAX) variance from substrate to substrate. These analyses reveal that these surfaces are topologically uniform with small LSPR variance from substrate to substrate. Further, we have utilized these patterned surfaces to acquire SERS spectral signatures of four intact, genetically distinct Bacillus spore species cultivated under identical growth conditions. Salient spectral signature features make it possible to discriminate among these genetically distinct spores. Additionally, partial least squares, a multivariate calibration method, has been used to develop personal-computer-borne algorithms useful for classification of unknown spore samples based solely on SERS spectral signatures. To our knowledge, this is the first report detailing application of these commercially available SERS-active substrates to identification of intact Bacillus spores.
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Affiliation(s)
- Troy A Alexander
- U.S Army Research Laboratory, Sensors and Electron Devices Directorate, Optics Branch-Biologically Inspired Devices and Sensors Team, AMSRD-ARL-SE-EO, Adephi, Maryland 20783, USA.
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276
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Sha MY, Penn S, Freeman G, Doering WE. Detection of human viral RNA via a combined fluorescence and SERS molecular beacon assay. NANOBIOTECHNOLOGY : THE JOURNAL AT THE INTERSECTION OF NANOTECHNOLOGY, MOLECULAR BIOLOGY, AND BIOMEDICAL SCIENCES 2007; 3:23-30. [PMID: 32218711 PMCID: PMC7091242 DOI: 10.1007/s12030-007-0003-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A dual-mode molecular beacon on a multiplexed substrate has been developed and applied to the measurement of unlabeled human viral RNA. The detection system is based on a combined surface-enhanced Raman scattering (SERS) and fluorescent molecular beacon assay that is assembled on Nanobarcodes™ particles. In this assay, a molecular beacon probe terminated with a fluorescent Raman label dye is conjugated to the metallic Nanobarcodes™ particles. The molecular beacon probe is a single-stranded oligonucleotide that has been designed with a hairpin structure that holds the dye at 3'-end close to the particle surface when the probe is attached through a 5'-thiol group. In this configuration, the SERS spectrum of the label was obtained and its fluorescence quenched because the dye is in very close proximity to a noble metal surface with nanoscale features (Nanobarcodes™ particles). The SERS signal decreased and the fluorescence signal increased when target viral RNA was captured by this molecular beacon probe. In addition, a hepatitis C virus reverse transcriptase-polymerase chain reaction (HCV RT-PCR) product was detected using this dual-mode beacon. The development of a multiplexed, label-free assay system with the reassurance offered by detection of two distinctly separate signals offers significant benefits for rapid molecular diagnostics.
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Affiliation(s)
- M. Y. Sha
- Oxonica Inc, 665 Clyde Avenue, Suite A, 94043 Mountain View, CA USA
| | - S. Penn
- Oxonica Inc, 665 Clyde Avenue, Suite A, 94043 Mountain View, CA USA
| | - G. Freeman
- Oxonica Inc, 665 Clyde Avenue, Suite A, 94043 Mountain View, CA USA
| | - W. E. Doering
- Oxonica Inc, 665 Clyde Avenue, Suite A, 94043 Mountain View, CA USA
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277
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278
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Liu YC, Yu CC, Hsu TC. Trace molecules detectable by surface-enhanced Raman scattering based on newly developed Ag and Au nanoparticles-containing substrates. Electrochem commun 2007. [DOI: 10.1016/j.elecom.2006.10.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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279
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Kim K, Lee HS, Kim NH. Silver-particle-based surface-enhanced resonance Raman scattering spectroscopy for biomolecular sensing and recognition. Anal Bioanal Chem 2007; 388:81-8. [PMID: 17318510 DOI: 10.1007/s00216-007-1182-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/26/2006] [Accepted: 02/02/2007] [Indexed: 10/23/2022]
Abstract
We demonstrate in this work that 2-microm-sized Ag (microAg) powders can be used as a core material for constructing biomolecular sensing/recognition units operating via surface-enhanced resonance Raman scattering (SERRS). This is possible because microAg powders are very efficient substrates for both the diffuse reflectance IR and the surface-enhanced Raman scattering-SERRS spectroscopic characterization of molecular adsorbates prepared in a similar manner on silver surfaces. Besides, the agglomeration of microAg particles in a buffer solution can be prevented by the layer-by-layer deposition of cationic and anionic polyelectrolytes such as poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA). In this particular study, we used rhodamine B isothiocyanate (RhBITC) as a SERRS marker molecule, and microAg powders adsorbed consecutively with RhBITC and PAH-PAA bilayers were finally derivatized with biotinylated poly(L-lysine). On the basis of the nature of the SERRS peaks of RhBITC, those microAg powders were confirmed to selectively recognize streptavidin molecules down to concentrations of 10(-10) g mL-1. Since a number of different molecules can be used as SERS-SERRS marker molecules, the present method proves to be an invaluable tool for multiplex biomolecular sensing/recognition via SERS and SERRS.
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Affiliation(s)
- Kwan Kim
- Laboratory of Intelligent Interfaces, Department of Chemistry, Seoul National University, Seoul, 151-742, South Korea.
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280
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Liu YC, Yu CC, Wang CC. Novel surface-enhanced Raman scattering-active silver substrates containing visible light-responsible Tio2 nanoparticles. ACTA ACUST UNITED AC 2007. [DOI: 10.1039/b618868k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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281
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Moskovits M, Jeong DH, Livneh T, Wu Y, Stucky GD. Engineering Nanostructures for Single-Molecule Surface-Enhanced Raman Spectroscopy. Isr J Chem 2006. [DOI: 10.1560/ijc_46_3_283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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282
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Karthikeyan B. Novel synthesis and optical properties of Sm3+ doped Au- polyvinyl alcohol nanocomposite films. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.10.113] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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283
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284
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Miljanić S, Frkanec L, Biljan T, Meić Z, Zinić M. Surface-enhanced Raman scattering on molecular self-assembly in nanoparticle-hydrogel composite. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:9079-81. [PMID: 17042511 DOI: 10.1021/la061521o] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Surface-enhanced Raman scattering has been applied to study weak intermolecular interactions between small organic gelling molecules involved in the silver nanoparticle-hydrogel composite formation. Assembly and disassembly of the gelator molecules in close vicinity to embedded silver nanoparticles were followed by changes in Raman intensity of the amide II and carboxyl vibrational bands, whereas the strength of the bands related to benzene modes remained constant. This implied that the gelator molecules were strongly attached to the silver particles through the benzene units, while participating in gel structure organization by intermolecular hydrogen bonding between oxalyl amide and carboxyl groups.
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Affiliation(s)
- Snezana Miljanić
- Laboratory of Analytical Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia.
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285
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Itoh T, Kikkawa Y, Biju V, Ishikawa M, Ikehata A, Ozaki Y. Variations in Steady-State and Time-Resolved Background Luminescence from Surface-Enhanced Resonance Raman Scattering-Active Single Ag Nanoaggregates. J Phys Chem B 2006; 110:21536-44. [PMID: 17064104 DOI: 10.1021/jp064070p] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We observed a background luminescence emission that was associated with surface-enhanced resonance Raman scattering (SERRS) of rhodamine 6G (R6G) molecules adsorbed on single Ag nanoaggregates and investigated the origin of the background luminescence. Thanks to the observation of single nanoaggregates, we clearly identified nanoaggregate-by-nanoaggregate variations in the steady-state and time-resolved background luminescence spectra of each nanoaggregate. From the variations in the steady-state spectra, two kinds of key properties were revealed. First, the background luminescence spectra were divided into four components: one fluorescence band corresponding to the monomers of R6G and three Lorentzian bands whose maxima were red-shifted from the fluorescence maximum of the monomer by several tens of nanometers. On the basis of the red-shifted luminescence maxima, and experimental and theoretical studies of background luminescence, we attributed the three background luminescences to fluorescence from aggregates (dimer and two kinds of higher-order aggregates) of R6G molecules on an Ag surface. Second, a positive correlation was observed between wavelengths of background luminescence maxima and wavelengths of plasmon resonance maxima. This positive correlation invoked the idea that the dipoles of both the background luminescence and the plasmon radiation are coupled with each other. From the key observations in the steady-state background luminescence spectra, we propose that two factors contribute to the variations in the steady-state background luminescence spectra; one is the aggregation (monomer, dimer, and two kinds of higher-order aggregates) of R6G molecules on an Ag surface, and the other is plasmon resonance maxima of single Ag nanoaggregates. Considering these two factors, we propose that the variations in the time-resolved background luminescence spectra are associated with deaggregation of R6G molecules (higher- to lower-order aggregates) and temporal shifts in the plasmon resonance maxima of single Ag nanoaggregates.
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Affiliation(s)
- Tamitake Itoh
- Nano-Bioanalysis Team, Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu Kagawa 761-0395, Japan.
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286
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Zou X, Dong S. Surface-Enhanced Raman Scattering Studies on Aggregated Silver Nanoplates in Aqueous Solution. J Phys Chem B 2006; 110:21545-50. [PMID: 17064105 DOI: 10.1021/jp063630h] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four different sizes of citrate-protected silver nanoplates with the corresponding in-plane dipole resonance band at 530, 619, 778, and 858 nm, respectively, are synthesized for surface-enhanced Raman scattering (SERS) study. Their aggregation behaviors are monitored by use of UV-vis spectroscopy. During the aggregation process, a marked red shift of the in-plane dipole resonance of silver nanoplates is observed, whereas other resonance modes of them only have small alterations in the site or intensity. Aggregated silver nanoplates can serve as active SERS substrates with an enhancement factor of about 4.5 x 10(5) using 2-aminothiophenol as a probing molecule. The SERS performance of silver nanoplates is even superior to the commonly used Lee-Meisel silver colloid, making them very attractive for SERS applications.
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Affiliation(s)
- Xiangqin Zou
- State Key Laboratory of Electroanalytic Chemistry, Changchun Institute of Applied Chemistry, Graduate School, Chinese Academy of Sciences, Changchun, Jilin 130022, China
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287
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Mosier-Boss PA. Optical properties of surface-enhanced Raman-active capture matrices. APPLIED SPECTROSCOPY 2006; 60:1148-56. [PMID: 17059667 DOI: 10.1366/000370206778664699] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Silver and gold colloidal particles can be immobilized on amine-derivatized magnetic microparticles. Once immobilized, the colloidal particles can be reacted with thiols to form a self-assembled monolayer (SAM). Earlier it was shown that the resultant derivatized magnetic microparticles, i.e., capture matrices, are surface-enhanced Raman (SERS) active and that they can be used to extract trace amounts of analyte from an aqueous sample. In this investigation, the optical properties of the capture matrices are examined. Imaging of these magnetic microparticles shows that the immobilized silver/gold colloidal particles exhibit blinking behavior. An increase in the SERS signals due to the SAM and the continuum is observed with constant laser illumination of these magnetic microparticles. Such an increase can be used to improve sensitivity. This increase in signal is attributed to the electromagnetic enhancement mechanism (EEM).
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Affiliation(s)
- P A Mosier-Boss
- SPAWAR Systems Center San Diego, Code 2373, San Diego, California 92152, USA.
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288
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Sztainbuch IW. The effects of Au aggregate morphology on surface-enhanced Raman scattering enhancement. J Chem Phys 2006; 125:124707. [PMID: 17014200 DOI: 10.1063/1.2338029] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have identified empirically a relationship between the surface morphology of small individual aggregates (<100 Au nanoparticles) and surface-enhanced Raman scattering (SERS) enhancement. We have found that multilayer aggregates generated greater SERS enhancement than aggregates limited to two-dimensional (2D) or one-dimensional structures, independent of the number of particles. SERS intensity was measured using the 730 cm(-1) vibrational mode of the adsorbed adenine molecule on 75 nm Au particles, at an excitation wavelength of 632.8 nm. To gain insight into these relationships and its mechanism, we developed a qualitative model that considers the collections of interacting Au nanoparticles of an individual aggregate as a continuous single entity that retains its salient features. We found the dimensions of the modeled surface features to be comparable with those found in rough metal surfaces, known to sustain surface plasmon resonance and generate strong SERS enhancement. Among the aggregates that we have characterized, a three 75 nm nanoparticle system was the smallest to generate strong SERS enhancement. However, we also identified single individual Au nanoparticles as SERS active at the same wavelength, but with a diameter twice in size. For example, we observed a symmetric SERS-active particle of 180 nm in diameter. Such individual nanoparticles generated SERS enhancement on the same order of magnitude as the small monolayer Au aggregates, an intensity value significantly stronger than predicted in recent theoretical studies. We also found that an aspect of our model that relates the dimensions of its features to SERS enhancement is also applicable to single individual Au particles. We conclude that the size of the nanoparticle itself, or the size of a protrusion of an irregularly shaped single Au particle, will contribute to SERS enhancement provided that its dimensions satisfy the conditions for plasmon resonance. In addition, by considering the ratio of the generated intensities of typical 2D Au aggregates to the enhancement of individual SERS-active particles, a value of approximately 2 is determined. Its moderate value suggests that it is not the aggregation effect that is responsible for much of the observed SERS enhancement but the surface region associated with the SERS-active site.
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Affiliation(s)
- Isaac W Sztainbuch
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
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289
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Yamamoto S, Watarai H. Surface-enhanced Raman spectroscopy of dodecanethiol-bound silver nanoparticles at the liquid/liquid interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:6562-9. [PMID: 16830998 DOI: 10.1021/la0603119] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Adsorption and domain formation of dodecanethiol (DT)-bound silver nanoparticles (SNPs) at the cyclohexane/water interface were studied by means of total internal reflection (TIR) light scattering microscopy and TIR surface-enhanced Raman scattering (SERS). By the TIR light scattering microscopy, the extent of the interfacial adsorption and domain formation of SNP was observed, which was produced by the reaction between citrate-reduced SNPs in the aqueous phase and DT in the cyclohexane phase. The Raman spectra of DT on SNP showed that the relative intensity ratios of gauche to trans conformers in the nu(C-S) band region decreased with the increase of the initial concentration of DT, suggesting the change from the liquidlike structure to the solidlike structure of the DT. The residue of the negative charges on the SNPs at the interface was detected by the resonance SERS (SERRS) peaks of the adsorbed cationic porphyrin, 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)-21H,23H-porphine (TMPyP). The efficiency of the interfacial SNPs domains as a SERS substrate for TMPyP strongly depended on the adsorption state of the DT.
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Affiliation(s)
- S Yamamoto
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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290
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Centeno SP, López-Tocón I, Arenas JF, Soto J, Otero JC. Selection Rules of the Charge Transfer Mechanism of Surface-Enhanced Raman Scattering: The Effect of the Adsorption on the Relative Intensities of Pyrimidine Bonded to Silver Nanoclusters. J Phys Chem B 2006; 110:14916-22. [PMID: 16869604 DOI: 10.1021/jp0621373] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Surface-enhanced Raman spectra (SERS) of pyrimidine recorded on a silver electrode have been analyzed on the basis of a resonant Raman (RR) process involving photoexcited charge transfer (CT) states of the metal-adsorbate surface complex. The main feature of the SERS of benzene and azine derivatives is the enhancement of the totally symmetric ring stretching mode 8a due to Franck-Condon contributions related to the CT transition. Although this behavior is observed in the SERS of pyrimidine, its spectrum is also characterized by the strong enhancement of the nontotally symmetric mode 8b. This peculiar feature can be explained only by the redistribution of the Franck-Condon factors between the 8ab pair of vibrations originated by the descent in symmetry occurring when pyrimidine is bonded to silver nanoclusters. This conclusion is a new evidence of the main role of the RR-CT enhancement mechanism in the SERS of aromatic molecules and shows once again the usefulness of the methodology developed by our group in order to analyze these complex spectra.
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Affiliation(s)
- Silvia P Centeno
- Department of Physical Chemistry, Faculty of Sciences, University of Malaga, E-29071 Malaga, Spain
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291
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Anderson DJ, Moskovits M. A SERS-Active System Based on Silver Nanoparticles Tethered to a Deposited Silver Film. J Phys Chem B 2006; 110:13722-7. [PMID: 16836316 DOI: 10.1021/jp055243y] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of SERS-active nanostructures were produced by exposing a freshly deposited silver film (fabricated to be as free from roughness as practicable) to a solution containing a mixture of 1-decanethiol (m) and 1,9-nonanedithiol (d) of varying concentrations of m to d, then allowing colloidal silver nanoparticles to interact with the surface. Silver nanoparticles were found to bind exclusively to films which were prepared from solutions with a nonzero concentration of the dithiol implying that the nanoparticles were tethered to the silver surface by the dithiol with one of the thiolate groups bound to the nanoparticle and the other to the silver film. Intense SERS spectra were observed even from samples in which the m/d concentration ratio was so large that the adsorbed molecules in the vicinity of only approximately 8 +/- 3 nanoparticles were illuminated by the diffraction-limited focused laser beam. At such high dilution, the molecules (numbering at most approximately 330) residing in the SERS "hot spots" associated with the approximately 8 nanoparticles consisted primarily of m (although, of course, for each nanoparticle, at least one molecule in the hot spot had to be d to serve as the linker). This was corroborated by the SERS spectra. An analysis is presented, which accounts for the fact that as the concentration ratio of m/d increases, the SERS intensity associated with bands belonging to m first increases to a maximum then decreases. The nanoparticle-metal film system presented here is a simple embodiment of a more general range of SERS-active sensing platforms in which a molecular tether is used to create a SERS hot spot that (although nanosized) is large enough to accommodate analyte molecules that cannot themselves function as linkers, which are subsequently detected by SERS at the few-molecule level.
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Affiliation(s)
- D J Anderson
- Department of Chemistry University of Toronto, Toronto, Ontario, Canada M5S 3H6
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292
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Zhou Q, Li X, Fan Q, Zhang X, Zheng J. Charge Transfer between Metal Nanoparticles Interconnected with a Functionalized Molecule Probed by Surface-Enhanced Raman Spectroscopy. Angew Chem Int Ed Engl 2006; 45:3970-3. [PMID: 16683285 DOI: 10.1002/anie.200504419] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Qun Zhou
- Department of Chemistry, Suzhou University, Suzhou 215006, P.R. China.
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293
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Zhou Q, Li X, Fan Q, Zhang X, Zheng J. Charge Transfer between Metal Nanoparticles Interconnected with a Functionalized Molecule Probed by Surface-Enhanced Raman Spectroscopy. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200504419] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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294
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Song W, Cheng Y, Jia H, Xu W, Zhao B. Surface enhanced Raman scattering based on silver dendrites substrate. J Colloid Interface Sci 2006; 298:765-8. [PMID: 16458915 DOI: 10.1016/j.jcis.2006.01.037] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 01/15/2006] [Accepted: 01/18/2006] [Indexed: 11/25/2022]
Abstract
A simple method of the reduction of AgNO3 by copper foil in aqueous medium was used to prepare silver dendrites, which can be used as a novel good reproducible surface enhanced Raman scattering (SERS) active substrate. The SERS spectra of 4-pyridinethiol on this novel substrate reflected the different SERS activities on the minuteness and strong Ag dendrites. The electromagnetic coupling enhancement and chemical enhancement mechanisms are used to explain the SERS effect.
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Affiliation(s)
- Wei Song
- Key Laboratory of Supramolecular Structure and Materials of Ministry of Education, Jilin University, 2699#, Qianjin Street, Changchun 130012, People's Republic of China
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295
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Wu SM, Zhao X, Zhang ZL, Xie HY, Tian ZQ, Peng J, Lu ZX, Pang DW, Xie ZX. Quantum-Dot-Labeled DNA Probes for Fluorescence In Situ Hybridization (FISH) in the MicroorganismEscherichia coli. Chemphyschem 2006; 7:1062-7. [PMID: 16625674 DOI: 10.1002/cphc.200500608] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Semiconductor quantum dots (QDs) as a kind of nonisotopic biological labeling material have many unique fluorescent properties relative to conventional organic dyes and fluorescent proteins, such as composition- and size-dependent absorption and emission, a broad absorption spectrum, photostability, and single-dot sensitivity. These properties make them a promising stable and sensitive label, which can be used for long-term fluorescent tracking and subcellular location of genes and proteins. Here, a simple approach for the construction of QD-labeled DNA probes was developed by attaching thiol-ssDNA to QDs via a metal-thiol bond. The as-prepared QD-labeled DNA probes had high dispersivity, bioactivity, and specificity for hybridization. Based on such a kind of probe with a sequence complementary to multiple clone sites in plasmid pUC18, fluorescence in situ hybridization of the tiny bacterium Escherichia coli has been realized for the first time.
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Affiliation(s)
- Sheng-Mei Wu
- College of Chemistry and Molecular Sciences and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, P. R. China
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296
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Kim K, Park HK, Kim NH. Silver-particle-based surface-enhanced Raman scattering spectroscopy for biomolecular sensing and recognition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:3421-7. [PMID: 16548610 DOI: 10.1021/la052912q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In this study, we demonstrate that 2-microm-sized Ag (microAg) powders can be used as a core material for constructing molecular sensing/recognition units operating via surface-enhanced Raman scattering (SERS). This is possible because microAg powders are very efficient substrates for both the infrared and Raman-spectroscopic characterization of molecular adsorbates prepared in a similar manner on silver surfaces; we can obtain an infrared spectrum of organic molecules adsorbed on microAg particles with a very high signal-to-noise ratio by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), and the Raman spectrum of organic monolayers on powdered silver is an SERS spectrum. The agglomeration of microAg particles in a highly concentrated buffer solution could be prevented by the layer-by-layer deposition of cationic and anionic polyelectrolytes such as poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA). In fact, prior to depositing PAA and PAH, 4-aminobenzenethiol (4-ABT) was assembled on the surfaces of the microAg particles as SERS markers. Because of the presence of amine groups of 4-ABT, PAA could be readily deposited on the microAg particles. On the other hand, the outermost PAA layer could also be derivatized with biotin-derivatized poly(L-lysine). The nonspecific interaction of poly(L-lysine) with proteins could be suppressed by grafting poly(ethylene glycol) into the biotin-derivatized poly(L-lysine) molecules. On the basis of the nature of the SERS peaks of 4-ABT, it was confirmed that these biotinylated microAg powders were effective in selectively recognizing the streptavidin arrays. Because a number of different molecules can be used as SERS-marker molecules, such as probable 4-ABT, commercially available microAg powders must be a prospective material in molecular sensing/recognition, particularly via SERS.
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Affiliation(s)
- Kwan Kim
- Laboratory of Intelligent Interfaces, School of Chemistry, Seoul National University, Seoul 151-742, Korea.
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297
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Malynych S, Chumanov G. Coupled planar silver nanoparticle arrays as refractive index sensors. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/1464-4258/8/4/s14] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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298
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Zhang X, Yonzon CR, Young MA, Stuart DA, Van Duyne RP. Surface-enhanced Raman spectroscopy biosensors: excitation spectroscopy for optimisation of substrates fabricated by nanosphere lithography. ACTA ACUST UNITED AC 2006; 152:195-206. [PMID: 16441180 DOI: 10.1049/ip-nbt:20050009] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the 28 years since its discovery, surface-enhanced Raman scattering (SERS) has progressed from model system studies of pyridine on a roughened silver electrode to state-of-the-art surface science studies and real-world sensing applications. Each year, the number of SERS publications increases as nanoscale material design techniques advance and the importance of trace analyte detection increases. To achieve the lowest limits of detection, both the relationship between surface nanostructure and laser excitation wavelength and the analyte-surface binding chemistry must be carefully optimised. This work exploits the highly tunable nature of nanoparticle optical properties to establish the optimisation conditions. Two methods are used to study the optimised conditions of the SERS substrate: plasmon-sampled and wavelength-scanned surfaced Raman excitation spectroscopy (SERES). The SERS enhancement condition is optimised when the energy of the localised surface plasmon resonance of the nanostructures lies between the energy of the excitation wavelength and the energy of the vibration band of interest. These optimised conditions enabled the development of SERS-based sensors for the detection of a Bacillus anthracis biomarker and glucose in a serum-protein matrix.
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Affiliation(s)
- X Zhang
- Department of Chemistry, Northwestern University, Evanston, IL 60201, USA
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299
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Chowdhury MH, Gant VA, Trache A, Baldwin A, Meininger GA, Coté GL. Use of surface-enhanced Raman spectroscopy for the detection of human integrins. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:024004. [PMID: 16674194 DOI: 10.1117/1.2187022] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Current research has revealed the importance of a class of cell surface proteins called integrins in various vital physiological functions such as blood clotting, regulation of blood pressure, tissue blood flow, and vascular remodeling. The key to integrin functionality is its ability to mediate force transmission by interacting with the extracellular matrix and cytoskeleton. In addition, they play a role in signal transduction via their connection with the proteins in focal adhesion (FA) points. To understand the complex mechanism of cell-cell and cell-extracellular matrix (ECM) adhesion that is responsible for these diverse biochemical interactions, it is necessary to identify the integrins on cells and monitor their interaction with various ligands. To this end, for the first time, we employ surface-enhanced Raman spectroscopy (SERS) to detect integrins. The results show the capability using SERS to detect the integrins to the nanomolar concentration regime and to distinguish between two different kinds of integrins, alphaVbeta3 and alpha5beta1, that are present in vascular smooth muscle cells (VSMCs). It is anticipated that the SERS approach will potentially help elucidate the mechanism of integrin-ligand interactions in a variety of phenomena of physiological importance.
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Affiliation(s)
- Mustafa H Chowdhury
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas 77843-3120, USA
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300
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Sládkova M, Vlcková B, Mojzes P, Slouf M, Naudin C, Le Bourdon G. Probing strong optical fields in compact aggregates of silver nanoparticles by SERRS of protoporphyrin IX. Faraday Discuss 2006; 132:121-34; discussion 147-58. [PMID: 16833112 DOI: 10.1039/b506247k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
TEM images and measurements of SERRS (surface-enhanced resonance Raman scattering) spectra as a function of the porphyrin concentrations in systems with unmodified and chloride-modified Ag nanoparticles and protoporphyrin IX (PPIX) are reported. TEM images have shown formation of compact aggregates in systems with chloride modified Ag nanoparticles, as opposed to systems with the unmodified particles constituted by isolated particles. SERRS spectra of PPIX as a function of PPIX concentration were measured and subjected to factor analysis. Two spectral components were identified and tentatively attributed to unperturbed PPIX and to Ag+ -PPIX surface species. Concentration value of the SERRS spectral detection limit of the latter species was determined to be nearly three orders of magnitude lower in the system with the compact aggregates than in the system with separated nanoparticles and achieves the value of 1 x 10(-10) M in a macrosampling Raman experiment. TEM images and SERRS-micro-Raman spectra of single compact aggregates of chloride-modified Ag nanoparticles incorporating PPIX molecules were acquired from a sample prepared by attachment of the aggregates to amine groups of derivatized, SiOx/formvar coated copper grids for TEM. The SERRS signal has shown large temporal fluctuations as well as variations from one aggregate to another. Within the signal fluctuations, a SERRS spectrum showing the characteristic bands of both SERRS spectral forms of PPIX and originating most probably from a few PPIX molecules located in hot spots in the interstices between the Ag nanoparticles, was obtained.
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Affiliation(s)
- Magdalena Sládkova
- Department of Physical and Macromolecular Chemistry, Charles University in Prague, Hlavova 2030, 128 40 Prague 2, Czech Republic
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