Flocculation of Ag nanoparticles elucidating adsorbed p-mercaptobenzoic acid by surface enhanced Raman scattering

Yu, Yingying; Handa, Saori; Yajima, Toru; Futamata, Masayuki

doi:10.1016/j.cplett.2013.01.015

Cited by 21 publications

(31 citation statements)

References 18 publications

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“…The SEHRS spectra obtained from the SEHRS probes at the incubation concentration in the culture medium show very weak signals, due to the relatively small number of reporter molecules in this experiment. Even though the space requirements of pMBA, 36 and also of 2-NAT on the silver surface yield complete coverage of the silver nanostructures with the molecules, the number of molecules in the ∼2 μm…”

Section: Sehrs Labels In Cell Culture Mediummentioning

confidence: 99%

Surface-enhanced hyper Raman hyperspectral imaging and probing in animal cells

et al. 2017

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scattering, that is, spontaneous, two-photon excited Raman scattering, of organic molecules becomes strong when it occurs as surface-enhanced hyper Raman scattering (SEHRS), in the proximity of plasmonic nanostructures. Its advantages over one-photon excited surface-enhanced Raman scattering (SERS) include complementary vibrational information resulting from different selection rules, probing of very small focal volumes, and beneficial excitation with long wavelengths. Here, imaging of macrophage cells by SEHRS is demonstrated, using SEHRS labels consisting of silver nanoparticles and two different molecules, 2-naphthalenethiol and para-mercaptobenzoic acid, that are excited offresonance. The vibrational signatures of the molecules are discriminated using hyperspectral analysis and provide information about the subcellular localization of the SEHRS probes. The SEHRS based hyperspectral imaging approach presented here uses principal component analysis (PCA) to localize the reporter molecules inside the cells and is augmented by hierarchical cluster analysis (HCA). The high sensitivity of SEHRS spectra with respect to small environmental changes can be utilized for mapping of physiological parameters in the endosomal system of the cells. This is illustrated by discussing the spatial distribution of endosomes of varying pH inside the cytosol.

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Section: Sehrs Labels In Cell Culture Mediummentioning

confidence: 99%

Surface-enhanced hyper Raman hyperspectral imaging and probing in animal cells

et al. 2017

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“…[4][5][6][7][8] Sulfuric acid, sodium hydroxide and various thiol molecules were purchased from Wako Pure Chemicals, and used without further purication. [4][5][6][7][8] Sulfuric acid, sodium hydroxide and various thiol molecules were purchased from Wako Pure Chemicals, and used without further purication.…”

Section: Methodsmentioning

confidence: 99%

“…[4][5][6][7][8][9] To overcome these issues, we exploited a self-assembled monolayer (SAM) of thiol molecules here, which to replace surface residuals and form occulates of MNPs. [4][5][6][7][8][9] To overcome these issues, we exploited a self-assembled monolayer (SAM) of thiol molecules here, which to replace surface residuals and form occulates of MNPs.…”

Section: Introductionmentioning

confidence: 99%

The critical importance of gap modes in surface enhanced Raman scattering

et al. 2015

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For efficient utilization of surface plasmons in surface enhanced Raman scattering (SERS), we investigated the gap modes in flocculates of metal nanoparticles (MNPs), and between MNPs and metal substrates under an external and an attenuated total reflection (ATR) geometry. First, the adsorbed state of thiol molecules and counter ions trapped in solutions were elucidated using flocculation-SERS, in which closely adjacent nanoparticles are formed by using interactions between MNPs and target species. Second, we obtained a pronounced enhancement of 10(5)-10(8) at a nanogap between gold nanoparticles (AuNPs) and various metal substrates even with a large damping under an external geometry. Markedly larger enhancement was obtained for larger AuNPs, by a factor of 10(3) for particles with a radius (r) of 50 nm compared with those of r=15 nm in this geometry. Finally, we attained an additional enhancement factor under an ATR geometry by a coupling of propagating surface plasmons with gap modes.

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“…Single molecule detection by Raman scattering has been investigated using a coupled localized surface plasmon (LSP) of adjacent metal nanostructures, by controlling the nanogap size and the adsorption of target molecules [1,2]. For this purpose, we have studied flocculates of silver and gold nanoparticles (AgNPs, and AuNPs), which are a few closely adjacent nanoparticles, providing various molecules with enormous SERS intensity in solutions [3][4][5][6][7]. Theoretical calculations suggest that one of AgNPs or AuNPs in flocculates can be replaced with metal substrates [8], such as Pd, Fe, Ni, Zn, Al and Pt [9][10][11][12] having large damping factors of surface plasmon, while providing enormous enhancement factors in SERS equivalent to those obtained in flocculates of AgNPs and AuNPs.…”

Section: Introductionmentioning

confidence: 99%

“…Indeed only cationic xanthene and triphenylmethane dyes are adsorbed on AgNPs to form flocculates [3,4]. Formation of self-assembled monolayers (SAM) of thiol molecules with functional groups such as carboxylic and amino groups is a promising way to form flocculates of AgNPs and to attain enormous SERS enhancement by trapping various molecules between neighboring AgNPs coated with SAMfilm [5,16].…”

Section: Introductionmentioning

confidence: 99%

Distinct Adsorbed States of DNA and RNA Bases Investigated by Flocculation-Assisted Surface Enhanced Raman Scattering

Mukaiyama

Yajima

Futamata

2015

e-J. Surf. Sci. Nanotech.

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We have succeeded in forming flocculates of gold nanoparticles (AuNPs) using DNA and RNA bases to obtain their surface enhanced Raman spectra. Adenine, guanine and cytosine molecules which possess a primary amino group (-NH2) formed flocculates at much lower concentration than uracil and thymine without an -NH2 group, suggesting a crucial role of an -NH2 group for adsorption of these base molecules on neighboring AuNPs. Detailed adsorption structure of base molecules was investigated using their SERS spectra at various pH in solutions and those for deuterated bases, comparing with those for bulk state and also by DFT calculations.

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Flocculation of Ag nanoparticles elucidating adsorbed p-mercaptobenzoic acid by surface enhanced Raman scattering

Cited by 21 publications

References 18 publications

Surface-enhanced hyper Raman hyperspectral imaging and probing in animal cells

Surface-enhanced hyper Raman hyperspectral imaging and probing in animal cells

The critical importance of gap modes in surface enhanced Raman scattering

Distinct Adsorbed States of DNA and RNA Bases Investigated by Flocculation-Assisted Surface Enhanced Raman Scattering

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