SEIRA studies of uracil adsorbed on wet-chemically prepared gold nanoparticles film on glass substrate – Effect of morphology of film

Kumar, Naveen; Thomas, Susy; Tokas, R.B.; Kshirsagar, R.J.

doi:10.1016/j.saa.2014.03.062

Cited by 13 publications

(14 citation statements)

References 36 publications

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“…Immobilization of p -PhCN samples on ultrathin (approximately nanometer) metal layers yields EFs of more than 1 order of magnitude, which is sufficiently large to study ML samples of organic molecules with low extinction coefficients at solid–liquid interfaces. These EFs are in good agreement with previously reported values (∼10–100) for organic molecules on structured noble-metal surfaces. ,,,− Taking into account the nonlinear nature of a 2D IR experiment, we note that this EF implies that one requires a 1600-fold (i.e., 40 2 ) smaller number of molecules on the surface of the NPs for a 2D ATR IR signal magnitudes that is equal to a bulk measurement (vide supra).…”

Section: Resultssupporting

confidence: 91%

Surface Enhancement in Ultrafast 2D ATR IR Spectroscopy at the Metal-Liquid Interface

2016

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We investigate surface enhancement in two-dimensional attenuated total reflectance infrared (2D ATR IR) spectroscopy from organic monolayers (MLs) at metal–liquid interfaces. We consider MLs from both aromatic and aliphatic organic samples equipped with nitrile and azide functional groups, both of which are widely used as local vibrational probes in ultrafast spectroscopy. Polarization-dependent 2D ATR IR spectroscopy indicates the excitation of local hot spots formed between gold (Au) nanoparticles as the dominant origin of signal enhancement. The highest enhancement factors (∼50) are observed in the case of aromatic nitrile MLs, whereas modest values (<10) are found for aliphatic azide and nitrile groups. Different contributions to signal enhancement are evaluated systematically and indicate the presence of both electromagnetic enhancement and contributions from molecular properties. The obtained enhancement factors are promising to allow 2D ATR IR spectroscopy to become applicable as a versatile technique for the detection of ultrafast structural dynamics in even low-absorbing organic MLs at solid–liquid interfaces.

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Section: Resultssupporting

confidence: 91%

Surface Enhancement in Ultrafast 2D ATR IR Spectroscopy at the Metal-Liquid Interface

2016

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“…SEIRA enhancement factors in the same range were demonstrated for vapor-deposited silver (EF between 5 and 150) [47] and platinum (EF around 10) [48] nanofilms, as well as for wet-chemical deposited spherical gold nanoparticles (EF around 5) [49]. The applied EF calculation method was similar to the approach used in [51], while one of the largest SEIRA enhancement factor was experimentally reported as 10 4 [52].…”

Section: Atr-seira Studies At Bovine Serum Albuminmentioning

confidence: 62%

Surface enhanced infrared absorption spectroscopy based on gold nanostars and spherical nanoparticles

Bibikova

Haas

López‐Lorente

et al. 2017

Analytica Chimica Acta

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Plasmonic anisotropic nanoparticles possess a number of hot spots on their surface due to the presence of sharp edges, tips or vertices, leading to a high electric field strength surrounding the nanostructures. In this paper, we explore different plasmonic nanostructures, including anisotropic gold nanostars (AuNSts) and spherical gold nanoparticles, in surface-enhanced infrared absorption spectroscopy (SEIRAS) in an attenuated total reflection (ATR) configuration. In our experiments, we observed up to 10-times enhancement of the infrared (IR) absorption of thioglycolic acid (TGA) and up to 2-times enhancement of signals for bovine serum albumin (BSA) protein on plasmonic nanostructure-based films deposited on a silicon (Si) internal reflection element (IRE) compared to bare Si IRE. The dependence of the observed enhancement on the amount of AuNSts present at the surface of the IRE has been demonstrated. Quantitative studies with both, TGA and BSA were performed, observing that the SEIRA signal can be correlated to the concentration of analyte molecules present within the evanescent field. The calibration curves in the presence of the AuNSts showed enhanced sensitivity as compared with the bare Si IRE. We finally compare efficiencies of anisotropic AuNSts and spherical citrate-capped and "bare" laser-synthesized gold nanoparticles as SEIRAS substrates for the detection of TGA and BSA. The signal obtained from AuNSts was at least 2 times higher for TGA molecules in comparison with spherical gold nanoparticles, which was explained by a more efficient generation of hot spots on anisotropic surface due to the presence of sharp edges, tips or vertices, leading to a high electric field strength surrounding the AuNSts.

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“…Compound 1, white amorphous powder, showed an IR absorbance band of carboxyl (1715, 1674 cm −1 ), aromatic (1674 cm −1 ), and amide group (1418 cm −1 ). IR spectrum of it was very similar to uracil with the exception for the absence of an amide moiety [7]. Its molecular weight and molecular formula were respectively 222 Da and C 8 Fig.…”

Section: Resultsmentioning

confidence: 91%

A 1,1′-biuracil from Epidermidibacterium keratini EPI-7 shows anti-aging effects on human dermal fibroblasts

Lee

Gwag

et al. 2019

Appl Biol Chem

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Our previous study we isolated novel bacterial stain, Epidermidibacterium keratini, called EPI-7 T from skin samples. Repeated column separation yielded one new pyrimidine compound, 1,1′-biuracil, from EPI-7 T culture solutions grown in R2A medium. Its chemical structure was determined based on spectroscopic data, IR, FAB/MS, and NMR. And 1,1′-biuracil and EPI-7 T culture solutions showed regulating effects of anti-aging associated mRNA expressions in UV-irradiated fibroblasts without toxicity in Hs68 cells. These results demonstrates the cosmetic potential of 1,1′-biuracil and EPI-7 T as anti-aging agents. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

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SEIRA studies of uracil adsorbed on wet-chemically prepared gold nanoparticles film on glass substrate – Effect of morphology of film

Cited by 13 publications

References 36 publications

Surface Enhancement in Ultrafast 2D ATR IR Spectroscopy at the Metal-Liquid Interface

Surface Enhancement in Ultrafast 2D ATR IR Spectroscopy at the Metal-Liquid Interface

Surface enhanced infrared absorption spectroscopy based on gold nanostars and spherical nanoparticles

A 1,1′-biuracil from Epidermidibacterium keratini EPI-7 shows anti-aging effects on human dermal fibroblasts

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