Surface-Enhanced Raman Spectroscopy of Two-Dimensional Tin Diselenide Nanoplates

Surface-enhanced Raman spectroscopy (SERS) is a powerful spectroscopy technique to detect and characterize molecules at a very low concentration level. The two-dimensional (2D) semi-conductor layered material, tin diselenide (SnSe2), is used as a new substrate for enhancing the Raman signals of adsorbed molecules. Three kinds of molecules—Rhodamine 6G (R6G), crystal violet (CV), and methylene blue (MB)—are used as probe molecules to evaluate the SERS performance of SnSe2. The Raman signals of different molecules can be enhanced by SnSe2 nanoplates (NPs). The distinguishable Raman signal of R6G molecules can be obtained for adsorbent concentrations as low as 10−17 mol/L. Based on a detailed analysis of the bandgap structure and opto-electrical properties of SnSe2 NPs, we discuss the process of charge transfer and the Raman enhancement mechanism of SnSe2 NP. The high Raman sensitivity of SnSe2 NPs is related to the charge transfer between molecules and SnSe2, 2D layered structure, and indirect bandgap of few-layered SnSe2. The research results will help to expand the application of SnSe2 in microanalysis, improve the measurement accuracy of SERS, and possibly find use in optoelectronic device integration.

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A Review on Applications of Two-Dimensional Materials in Surface-Enhanced Raman Spectroscopy

International Journal of Spectroscopy ◽

10.1155/2018/4861472 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 13

Author(s):

Ming Xia

Keyword(s):

Raman Spectroscopy ◽

2D Materials ◽

Surface Enhanced Raman Spectroscopy ◽

Great Promise ◽

Two Dimensional ◽

Raman Enhancement ◽

Two Dimensional Materials ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Recent Developments

Two-dimensional (2D) materials, such as graphene and MoS2, have been attracting wide interest in surface enhancement Raman spectroscopy. This perspective gives an overview of recent developments in 2D materials’ application in surface-enhanced Raman spectroscopy. This review paper focuses on the applications of using bare 2D materials and metal/2D material hybrid substrate for Raman enhancement. The Raman enhancing mechanism of 2D materials will also be discussed. The progress covered herein shows great promise for widespread adoption of 2D materials in SERS application.

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Rapid uropathogen identification using surface enhanced Raman spectroscopy active filters

Scientific Reports ◽

10.1038/s41598-021-88026-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Simon D. Dryden ◽

Salzitsa Anastasova ◽

Giovanni Satta ◽

Alex J. Thompson ◽

Daniel R. Leff ◽

...

Keyword(s):

Raman Spectroscopy ◽

Bacterial Infections ◽

Surface Enhanced Raman Spectroscopy ◽

Active Filters ◽

Raman Signal ◽

Rapid Diagnostics ◽

Bacterial Classification ◽

Surface Enhanced ◽

Surface Enhanced Raman

AbstractUrinary tract infection is one of the most common bacterial infections leading to increased morbidity, mortality and societal costs. Current diagnostics exacerbate this problem due to an inability to provide timely pathogen identification. Surface enhanced Raman spectroscopy (SERS) has the potential to overcome these issues by providing immediate bacterial classification. To date, achieving accurate classification has required technically complicated processes to capture pathogens, which has precluded the integration of SERS into rapid diagnostics. This work demonstrates that gold-coated membrane filters capture and aggregate bacteria, separating them from urine, while also providing Raman signal enhancement. An optimal gold coating thickness of 50 nm was demonstrated, and the diagnostic performance of the SERS-active filters was assessed using phantom urine infection samples at clinically relevant concentrations (105 CFU/ml). Infected and uninfected (control) samples were identified with an accuracy of 91.1%. Amongst infected samples only, classification of three bacteria (Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae) was achieved at a rate of 91.6%.

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Surface Enhanced Raman Spectroscopy With Electrodeposited Copper Ultramicro-Wires With/Without Silver Nanostars Decoration

Nanomaterials ◽

10.3390/nano11020518 ◽

2021 ◽

Vol 11 (2) ◽

pp. 518

Author(s):

Margherita Longoni ◽

Maria Sole Zalaffi ◽

Lavinia de Ferri ◽

Angela Maria Stortini ◽

Giulio Pojana ◽

...

Keyword(s):

Raman Spectroscopy ◽

Surface Enhanced Raman Spectroscopy ◽

Anodized Aluminum ◽

Anodized Aluminum Oxide ◽

Electrochemical Preparation ◽

Deposition Parameters ◽

Raman Enhancement ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Materials Used

The electrochemical preparation of arrays of copper ultramicrowires (CuUWs) by using porous membranes as templates is critically revisited, with the goal of obtaining cheap but efficient substrates for surface enhanced Raman spectroscopy (SERS). The role of the materials used for the electrodeposition is examined, comparing membranes of anodized aluminum oxide (AAO) vs. track-etched polycarbonate (PC) as well as copper vs. glassy carbon (GC) as electrode material. A voltammetric study performed on bare electrodes and potentiostatic tests on membrane coated electrodes allowed the optimization of the deposition parameters. The final arrays of CuUWs were obtained by chemical etching of the template, with NaOH for AAO and CH2Cl2 for PC. After total etching of the template, SERS spectra were recorded on CuUWs using benzenethiol as SERS probe with known spectral features. The CuUW substrates displayed good SERS properties, providing enhancement factor in the 103–104 range. Finally, it was demonstrated that higher Raman enhancement can be achieved when CuUWs are decorated with silver nanostars, supporting the formation of SERS active hot-spots at the bimetallic interface.

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Fabrication-friendly polarization-sensitive plasmonic grating for optimal surface-enhanced Raman spectroscopy

Journal of the European Optical Society Rapid Publications ◽

10.1186/s41476-020-00144-5 ◽

2020 ◽

Vol 16 (1) ◽

Author(s):

Arpan Dutta ◽

Tarmo Nuutinen ◽

Khairul Alam ◽

Antti Matikainen ◽

Peng Li ◽

...

Keyword(s):

Raman Spectroscopy ◽

Fill Factor ◽

Surface Enhanced Raman Spectroscopy ◽

Transverse Magnetic ◽

Raman Signal ◽

Optical Resonance ◽

Excitation Light ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Plasmonic Gratings

Abstract Plasmonic nanostructures are widely utilized in surface-enhanced Raman spectroscopy (SERS) from ultraviolet to near-infrared applications. Periodic nanoplasmonic systems such as plasmonic gratings are of great interest as SERS-active substrates due to their strong polarization dependence and ease of fabrication. In this work, we modelled a silver grating that manifests a subradiant plasmonic resonance as a dip in its reflectivity with significant near-field enhancement only for transverse-magnetic (TM) polarization of light. We investigated the role of its fill factor, commonly defined as a ratio between the width of the grating groove and the grating period, on the SERS enhancement. We designed multiple gratings having different fill factors using finite-difference time-domain (FDTD) simulations to incorporate different degrees of spectral detunings in their reflection dips from our Raman excitation (488 nm). Our numerical studies suggested that by tuning the spectral position of the optical resonance of the grating, via modifying their fill factor, we could optimize the achievable SERS enhancement. Moreover, by changing the polarization of the excitation light from transverse-magnetic to transverse-electric, we can disable the optical resonance of the gratings resulting in negligible SERS performance. To verify this, we fabricated and optically characterized the modelled gratings and ensured the presence of the desired detunings in their optical responses. Our Raman analysis on riboflavin confirmed that the higher overlap between the grating resonance and the intended Raman excitation yields stronger Raman enhancement only for TM polarized light. Our findings provide insight on the development of fabrication-friendly plasmonic gratings for optimal intensification of the Raman signal with an extra degree of control through the polarization of the excitation light. This feature enables studying Raman signal of exactly the same molecules with and without electromagnetic SERS enhancements, just by changing the polarization of the excitation, and thereby permits detailed studies on the selection rules and the chemical enhancements possibly involved in SERS.

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