In the present work we study the surface-enhanced resonant Raman scattering (SERRS) and fluorescence (SEF) spectra of a general model molecule confined in metallic dimers consisting of Ag, Au and hybrid AuAg nanoparticles (NPs). The electromagnetic (EM) enhancement factors were simulated by the generalized Mie scatting method and the scattering cross section of the molecules were obtained by density-matrix calculations. The influence of the size of the NPs and the separation between the dimer on the Raman scattering and fluorescence were systematically studied and analyzed in detail. It was found that the SERRS mainly related to EM enhancement and the SEF depended on the competition between EM enhancement and quantum yield, both of which could be controlled by tuning the radius and separation of the metallic dimers. The optimal radius of the NPs for SERRS were found to be around 30 nm for AgNPs, 40 nm for AuNPs and 50 nm for hybrid AuAgNPs. The strongest Raman enhancement as predicted by the theoretical simulations were 6.2 × 10, 1.5 × 10 and 5.2 × 10 for the three types of structures, respectively. These results could offer valuable information for the design of metallic substrates for surface enhanced Raman and fluorescence measurements.
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http://dx.doi.org/10.1038/s41598-018-20328-x | DOI Listing |
Sci Rep
December 2024
Jihua Laboratory, Foshan, 528000, China.
Surface-enhanced Raman scattering (SERS) technology has attracted more and more attention due to its high sensitivity, low water interference, and quick measurement. Constructing high-performance SERS substrates with high sensitivity, uniformity and reproducibility is of great importance to put the SERS technology into practical application. In this paper, we report a simple fabrication process to construct dense silver-coated PMMA nanoparticles-on-a-mirror SRES substrates.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610, Prague, Czech Republic; Department of Analytical Chemistry, University of Chemistry and Technology, Technická 5, 16628 Prague, Czech Republic. Electronic address:
Water is a greatly convenient solvent in Raman spectroscopy. However, non-additive effects sometimes make its signal difficult to subtract. To understand these effects, spectra for clusters of model ions, including transition metal complexes and water molecules, were simulated and analyzed.
View Article and Find Full Text PDFChem Biomed Imaging
December 2024
Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States.
Nanoscale surface topography is an effective approach in modulating cell-material interactions, significantly impacting cellular and nuclear morphologies, as well as their functionality. However, the adaptive changes in cellular metabolism induced by the mechanical and geometrical microenvironment of the nanotopography remain poorly understood. In this study, we investigated the metabolic activities in cells cultured on engineered nanopillar substrates by using a label-free multimodal optical imaging platform.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Agricultural Technology, Center for Precision Agriculture, Norwegian Institute of Bioeconomy Research (NIBIO), Nylinna 226 2849, Kapp, Norway.
Raman spectroscopy is a powerful and non-invasive analytical method for determining the chemical composition and molecular structure of a wide range of materials, including complex biological tissues. However, the captured signals typically suffer from interferences manifested as noise and baseline, which need to be removed for successful data analysis. Effective baseline correction is critical in quantitative analysis, as it may impact peak signature derivation.
View Article and Find Full Text PDFTalanta
December 2024
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China. Electronic address:
The proliferation of micro/nanoplastics (MNPs) has emerged as a pivotal environmental issue, largely due to their potential for human exposure. Consequently, the development of sensitive and efficient detection methodologies is paramount for elucidating their environmental footprint. Here, we report a novel three-dimensional (3D) surface-enhanced Raman scattering (SERS) sensor, which integrate TiCT/TiO/WO semiconductor heterostructure, for the rapid and sensitive detection of MNPs in environmental matrices.
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