scholarly journals SERS background imaging – A versatile tool towards more reliable SERS analytics

2021 ◽  
Author(s):  
Paul Ebersbach ◽  
Ute Münchberg ◽  
Erik Freier
Keyword(s):  
Sampling Error ◽  
Hot Spot ◽  
Sers Substrate ◽  
Structure Property ◽  
Contrast Imaging ◽  
Structure Property Relationships ◽  
High Contrast Imaging ◽  
Surface Enhanced Raman ◽  
Versatile Tool ◽  
Background Continuum

Abstract Surface-enhanced Raman scattering (SERS) is a highly selective and sensitive straightforward analytical method, which is however not yet established in routine analysis due to a lack of reliability and reproducibility. To address this limitation, we show the distinct correlation of the ever-present but often neglected broad SERS background continuum with the SERS signal intensity of the analyte and how to exploit this correlation for an easy-to-handle, automatable and more reliable SERS measurement. First, fast and high-contrast imaging of the SERS substrate is performed for hot spot localisation utilizing the SERS background. Subsequently, highly enhanced SERS spectra are recorded at the centre of these spots. Furthermore, we correlate our SERS background imaging with other optical imaging modalities and electron microscopy to assess structure-property relationships. Monte Carlo simulations based on actual measurements illustrate the sampling error of a conventional SERS experiment and the advantages our method provides.

scholarly journals SERS background imaging – A versatile tool towards more reliable SERS analytics

2020 ◽  
Author(s):  
Paul Ebersbach ◽  
Ute Münchberg ◽  
Erik Freier
Keyword(s):  
Sampling Error ◽  
Hot Spot ◽  
Sers Substrate ◽  
Structure Property ◽  
Contrast Imaging ◽  
Structure Property Relationships ◽  
High Contrast Imaging ◽  
Surface Enhanced Raman ◽  
Versatile Tool ◽  
Background Continuum

Abstract Surface-enhanced Raman scattering (SERS) is a highly selective and sensitive straightforward analytical method, which is however not yet established in routine analysis due to a lack of reliability and reproducibility. To address this limitation, we show the distinct correlation of the ever-present but often neglected broad SERS background continuum with the SERS signal intensity of the analyte and how to exploit this correlation for an easy-to-handle, automatable and more reliable SERS measurement. First, fast and high-contrast imaging of the SERS substrate is performed for hot spot localisation utilizing the SERS background. Subsequently, highly enhanced SERS spectra are recorded at the centre of these spots. Furthermore, we correlate our SERS background imaging with other optical imaging modalities and electron microscopy to assess structure-property relationships. Monte Carlo simulations based on actual measurements illustrate the sampling error of a conventional SERS experiment and the advantages our method provides.

scholarly journals SERS Background Imaging – a Versatile Tool Towards More Reliable SERS Analytics

2020 ◽  
Author(s):  
Paul Ebersbach ◽  
Ute Münchberg ◽  
Erik Freier
Keyword(s):  
Sampling Error ◽  
Hot Spot ◽  
Measurement Procedure ◽  
Sers Spectrum ◽  
Sers Substrate ◽  
Structure Property ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
Surface Enhanced Raman ◽  
Versatile Tool

<div>Surface-enhanced Raman scattering (SERS) is a highly selective and sensitive straightforward analytical method, which is however not yet established in routine analysis due to a lack of reliability and reproducibility. Here we utilise the broad SERS continuum background (SERS-BG) accompanying every SERS measurement as a versatile tool towards more reliable SERS analytics. We apply a heterogeneous gold SERS substrate immersed with an adenosine triphosphate solution to show that the integrated SERS-BG distinctly correlates with the intensity of the analyte signals in the SERS spectrum. Based on this relationship we introduce an easy-to-handle, automatable and more reliable SERS measurement procedure starting with fast and high-contrast imaging of the SERS substrate followed by hot spot localisation and recording of highly enhanced SERS spectra at the centre of the diffraction-limited spot. We further demonstrate the applicability of SERS-BG imaging by combining it with other optical modalities and electron microscopy to assess structure-property relationships. Additionally, we perform Monte-Carlo simulations to evaluate the sampling error in SERS experiments highlighting the advantages of our method over conventional SERS experiments.</div>

scholarly journals SERS Background Imaging – a Versatile Tool Towards More Reliable SERS Analytics

2020 ◽  
Author(s):  
Paul Ebersbach ◽  
Ute Münchberg ◽  
Erik Freier
Keyword(s):  
Sampling Error ◽  
Hot Spot ◽  
Measurement Procedure ◽  
Sers Spectrum ◽  
Sers Substrate ◽  
Structure Property ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
Surface Enhanced Raman ◽  
Versatile Tool

<div>Surface-enhanced Raman scattering (SERS) is a highly selective and sensitive straightforward analytical method, which is however not yet established in routine analysis due to a lack of reliability and reproducibility. Here we utilise the broad SERS continuum background (SERS-BG) accompanying every SERS measurement as a versatile tool towards more reliable SERS analytics. We apply a heterogeneous gold SERS substrate immersed with an adenosine triphosphate solution to show that the integrated SERS-BG distinctly correlates with the intensity of the analyte signals in the SERS spectrum. Based on this relationship we introduce an easy-to-handle, automatable and more reliable SERS measurement procedure starting with fast and high-contrast imaging of the SERS substrate followed by hot spot localisation and recording of highly enhanced SERS spectra at the centre of the diffraction-limited spot. We further demonstrate the applicability of SERS-BG imaging by combining it with other optical modalities and electron microscopy to assess structure-property relationships. Additionally, we perform Monte-Carlo simulations to evaluate the sampling error in SERS experiments highlighting the advantages of our method over conventional SERS experiments.</div>

Atomic Scale Analysis of a YSZ Bicrystal Grain Boundary

2001 ◽  
Vol 7 (S2) ◽  
pp. 400-401
Author(s):  
Y. Lei ◽  
Y. Ito ◽  
N. D. Browning
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Bulk Material ◽  
Atomic Scale ◽  
Structure Property ◽  
Contrast Imaging ◽  
Structure Property Relationships ◽  
Commercial Applications ◽  
Z Contrast ◽  
Electron Energy Loss

Yttria-stabilized zirconia (YSZ) has been the subject of many experimental and theoretical studies, due to the commercial applications of zirconia-based ceramics in solid state oxide fuel cells. Since the grain boundaries usually dominate the overall macroscopic performance of the bulk material, it is essential to develop a fundamental understanding of their structure-property relationships. Previous research has been performed on the atomic structure of grain boundaries in YSZ, but no precise atomic scale compositional and chemistry characterization has been carried out. Here we report a detailed analytical study of an [001] symmetric 24° bicrystal tilt grain boundary in YSZ prepared with ∼10 mol % Y2O3 by Shinkosha Co., Ltd by the combination of Z-contrast imaging and electron energy loss spectroscopy (EELS).The experimental analysis of the YSZ sample was carried out on a 200kV Schottky field emission JEOL 201 OF STEM/TEM4.

scholarly journals Three-Dimensional Hierarchical Reticular Nanostructure of Fulfora candelaria Wing Decorated by Ag Nanoislands as Practical SERS-Active Substrates

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 905 ◽  
Author(s):  
Mingli Wang ◽  
Yuhong Wang ◽  
Xiaoya Yan ◽  
Xin Sun ◽  
Guochao Shi ◽  
...  
Keyword(s):  
Hot Spot ◽  
Three Dimensional ◽  
Fdtd Simulation ◽  
Raman Signal ◽  
Sers Substrate ◽  
Practical Applications ◽  
Recognition Ability ◽  
Surface Enhanced Raman ◽  
Signal Sensitivity ◽  
Biological Substrates

Although surface-enhanced Raman scattering (SERS) technology has been widely explored nowadays in various fields, the fabrication of practical SERS-active substrates with prominent recognition ability for various analyte molecules is still defective. Natural Fulfora candelaria wing (FCW) with three-dimensional (3D) hierarchical reticular nanostructure was selected as a new bioscaffold for rough silver (Ag) nanoislands to be assembled on to prepare a practical SERS substrate (Ag/FCW substrate). By adjusting the sputtering time of metal Ag, the morphology of the substrates could be easily tuned to control the formation and distribution of “hot spots”. Three-dimensional finite-difference time-domain (3D-FDTD) simulation indicated that the excellent SERS performance under optimal morphology was ascribed to the local enhanced electric field in rough Ag surface and effective “hot spot” areas. The SERS measurement results show that the optimal Ag/FCW substrates had high SERS performance in terms of Raman signal sensitivity, reproducibility, uniformity and recognition ability for various analyte molecules. Coupled with flexibility of the biological substrates and the cost effectiveness, the sensitive SERS detection of varied analytes based on Ag/FCW substrates offered great potential for practical applications.

scholarly journals Quantitative SERS by hot spot normalization – surface enhanced Rayleigh band intensity as an alternative evaluation parameter for SERS substrate performance

2017 ◽  
Vol 205 ◽  
pp. 491-504 ◽  
Author(s):  
Haoran Wei ◽  
Alexis McCarthy ◽  
Junyeob Song ◽  
Wei Zhou ◽  
Peter J. Vikesland
Keyword(s):  
Hot Spot ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Alternative Evaluation ◽  
Plasmonic Nanoparticle ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Excitation Volume ◽  
Quantitative Sers

The performance of surface-enhanced Raman spectroscopy (SERS) substrates is typically evaluated by calculating an enhancement factor (EF). However, it is challenging to accurately calculate EF values since the calculation often requires the use of model analytes and requires assumptions about the number of analyte molecules within the laser excitation volume. Furthermore, the measured EF values are target analyte dependent and thus it is challenging to compare substrates with EF values obtained using different analytes. In this study, we propose an alternative evaluation parameter for SERS substrate performance that is based on the intensity of the surface plasmon enhanced Rayleigh band (IRayleigh) that originates from the amplified spontaneous emission (ASE) of the laser. Compared to the EF, IRayleigh reflects the enhancing capability of the substrate itself, is easy to measure without the use of any analytes, and is universally applicable for the comparison of SERS substrates. Six SERS substrates with different states (solid, suspended in liquid, and hydrogel), different plasmonic nanoparticle identities (silver and gold), as well as different nanoparticle sizes and shapes were used to support our hypothesis. The results show that there are excellent correlations between the measured SERS intensities and IRayleigh as well as between the SERS homogeneity and the variation of IRayleigh acquired with the six SERS substrates. These results suggest that IRayleigh can be used as an evaluation parameter for both SERS substrate efficiency and reproducibility.

Atomic structure determination of NIO-ZRO2(CaO) and NI-ZRO2(CaO) interfaces using Z-contrast imaging and EELS

1996 ◽  
Vol 54 ◽  
pp. 106-107
Author(s):  
E.C. Dickey ◽  
V.P. Dravid ◽  
P. Nellist ◽  
D.J. Wallis ◽  
N. D. Browning ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Bulk Material ◽  
Interface Structure ◽  
Structure Property ◽  
Contrast Imaging ◽  
Spatially Resolved ◽  
Structure Property Relationships ◽  
Powerful Approach ◽  
Resolution Imaging ◽  
Z Contrast

Combining atomic-resolution imaging with spatially resolved electron energy loss spectroscopy (EELS) is a powerful approach to probing the geometric, chemical and electronic aspects of internal interfaces. By elucidating these interrelated constituents of interface structure, one can begin to understand the influence of the interface atomic structure on relevant bulk material properties, deducing atomic structure/property relationships. The combined Z-contrast and EELS approach was applied to two types of heterophase interfaces: oxide-oxide (NiO-ZrO2) and metal-oxide (Ni-ZrO2). The interface structure will be discussed in light of these experiments and compared to previous HREM results.

scholarly journals Tannin-furanic foams used as biomaterial substrates for SERS sensing in possible wastewater filter applications

2021 ◽  
Vol 8 (11) ◽  
pp. 115404
Author(s):  
Gebhard Sabathi ◽  
Andreas Reyer ◽  
Nicola Cefarin ◽  
Thomas Sepperer ◽  
Jonas Eckardt ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Hot Spot ◽  
Surface Enhanced Raman Spectroscopy ◽  
Silver Layer ◽  
Sers Substrate ◽  
Malachite Green Dye ◽  
Relative Standard ◽  
Surface Enhanced Raman ◽  
Potential Applications ◽  
Cost Efficient

Abstract Simple substrates for surface enhanced Raman spectroscopy (SERS), producible in a cost-efficient way, are of growing interest both for scientific and for environmental applications. In this study, we demonstrate the use of three types of bio-based tannin-furanic rigid foams as precursor materials for SERS substrates. Coated with a silver layer, these substrates allowed the detection of several well-known analytes in the mM regime by Raman spectroscopy. Specific optimization of the standard tannin-furanic foam morphology by tuning the chemical synthesis led to a smaller and more homogeneously distributed pore structure, supplying more active hot spot areas. Thus, we obtained a significant increase and a lower relative standard deviation (RSD) of the SERS signal recorded over the mapped SERS substrate area, for several analytes, in particular for Malachite Green dye. This work represents a feasibility study opening several potential applications of this biopolymers in fields such as the detection of water pollutants, virtually combining filtration and SERS capabilities driven by a controlled porosity.

Investigating Atomic Scale Structure-property Relationships at Grain Boundaries

1998 ◽  
Vol 4 (S2) ◽  
pp. 790-791
Author(s):  
N. D. Browning ◽  
H. O. Moltaji ◽  
E. M. James ◽  
S. Stemmer ◽  
J. P. Buban ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Atomic Scale ◽  
Structure Property ◽  
Contrast Imaging ◽  
Structure Property Relationships ◽  
Unique Interpretation ◽  
Conventional Structure ◽  
Compositional Changes ◽  
Z Contrast

Although grain boundaries are known to dominate the bulk properties of many technologically important materials, in most cases there is no fundamental atomic scale understanding of why they should have such an effect. One of the problems in developing this understanding is that conventional structure determination techniques, such as phase contrast imaging in TEM or Z-contrast imaging in STEM, produce only a 2-dimensional projection of the crystal structure. Atomic scale compositional changes must be simulated and a unique interpretation is clouded by boundary reconstructions and strain effects. Furthermore, neither technique provides any information on the local changes in the electronic structure that are critical for both the electrical and mechanical properties of the boundary.EELS provides a means to quantify local changes in both composition and electronic structure. However, without a knowledge of the structure, interpretation of any observed changes at grain boundaries is extremely difficult.

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

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