scholarly journals Genetic Algorithm-Driven Surface-Enhanced Raman Spectroscopy Substrate Optimization

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2905
Author(s):  
Buse Bilgin ◽  
Cenk Yanik ◽  
Hulya Torun ◽  
Mehmet Cengiz Onbasli
Keyword(s):  
Genetic Algorithm ◽  
Raman Spectroscopy ◽  
Strong Electric Field ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Sers Substrate ◽  
Design Constraints ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive and molecule-specific detection technique that uses surface plasmon resonances to enhance Raman scattering from analytes. In SERS system design, the substrates must have minimal or no background at the incident laser wavelength and large Raman signal enhancement via plasmonic confinement and grating modes over large areas (i.e., squared millimeters). These requirements impose many competing design constraints that make exhaustive parametric computational optimization of SERS substrates prohibitively time consuming. Here, we demonstrate a genetic-algorithm (GA)-based optimization method for SERS substrates to achieve strong electric field localization over wide areas for reconfigurable and programmable photonic SERS sensors. We analyzed the GA parameters and tuned them for SERS substrate optimization in detail. We experimentally validated the model results by fabricating the predicted nanostructures using electron beam lithography. The experimental Raman spectrum signal enhancements of the optimized SERS substrates validated the model predictions and enabled the generation of a detailed Raman profile of methylene blue fluorescence dye. The GA and its optimization shown here could pave the way for photonic chips and components with arbitrary design constraints, wavelength bands, and performance targets.

scholarly journals Fabrication of Silver Nanodendrites on Copper for Detecting Rhodamine 6G in Chili Powder Using Surface-enhanced Raman Spectroscopy

2021 ◽  
Vol 31 (4) ◽  
Author(s):  
Quynh-Ngan Luong ◽  
Tran Cao Dao ◽  
Thi Thu Vu ◽  
Manh Cuong Nguyen ◽  
Nhu Duong Nguyen
Keyword(s):  
Raman Spectroscopy ◽  
Rhodamine 6G ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Simple Method ◽  
Sers Substrates ◽  
Highly Active ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Silver Nanodendrites

Surface-enhanced Raman spectroscopy (SERS) is increasingly being used as a method for detecting traces of contaminants in a variety of specimens. In order to maximize SERS’s performance, the most important thing is to have highly active SERS substrates. In this report, we present a simple method for synthesizing silver nanodendrites (AgNDs) on the surface of a copper (Cu) plate using chemical deposition method. The results showed that, after fabrication, a large number of fern-like AgNDs formed on the Cu surface. These AgNDs are distributed evenly across the entire Cu surface with a relatively thick density. The prepared AgNDs were applied as SERS substrates for detecting Rhodamine 6G (R6G) in chili powders. The results showed that, using the prepared AgNDs substrates, as low as 10−10 M R6G in chili powders can be detected. This demonstrates the applicability of fabricated AgNDs as a highly active SERS substrate.

scholarly journals Liquid Surface-Enhanced Raman Spectroscopy (SERS) Sensor-Based Au-Ag Colloidal Nanoparticles for Easy and Rapid Detection of Deltamethrin Pesticide in Brewed Tea

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Affi Nur Hidayah ◽  
Djoko Triyono ◽  
Yuliati Herbani ◽  
Rosari Saleh
Keyword(s):  
Raman Spectroscopy ◽  
Liquid Surface ◽  
Limit Of Detection ◽  
Surface Enhanced Raman Spectroscopy ◽  
Ease Of Use ◽  
Raman Signal ◽  
Colloidal Nanoparticles ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Deltamethrin pesticides can cause inflammation, nephrotoxicity and hepatotoxicity as well as affect the activity of antioxidant enzymes in tissues. As a result of this concern, there is a rising focus on the development of fast and reliable pesticide residue testing to minimise potential risks to humans. The goal of this study is to use Au-Ag colloid nanoparticles as liquid surface-enhanced Raman spectroscopy (SERS) to improve the Raman signal in the detection of deltamethrin pesticide in a brewed tea. The liquid SERS system is fascinating to study due to its ease of use and its unlikeliness to cause several phenomena, such as photo-bleaching, combustion, sublimation and even photo-catalysis, which can interfere with the Raman signal, as shown in the SERS substrate. Our liquid SERS system is simpler than previous liquid SERS systems that have been reported. We performed the detection of pesticide analyte directly on brewed tea, without diluting it with ethanol or centrifuging it. Femtosecond laser-induced photo-reduction was employed to synthesise the liquid SERS of Au, Au-Ag, and Ag colloidal nanoparticles. The SERS was utilised to detect deltamethrin pesticide in brewed tea. The result showed that liquid SERS-based Ag NPs significantly enhance the Raman signal of pesticides compared with liquid SERS-based Au NPs and Au-Ag Nanoalloys. The maximum residue limits (MRLs) in tea in Indonesia are set at 10 ppm. Therefore, this method was also utilised to detect and improve, to 0.01 ppm, the deltamethrin pesticide Limit of Detection (LOD).

scholarly journals Surface-Enhanced Raman Spectroscopy for Molecule Characterization: HIM Investigation into Sources of SERS Activity of Silver-Coated Butterfly Scales

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1741
Author(s):  
Hiroyuki Takei ◽  
Kazuki Nagata ◽  
Natalie Frese ◽  
Armin Gölzhäuser ◽  
Takayuki Okamoto
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Metal Nanostructures ◽  
Butterfly Species ◽  
Sers Substrate ◽  
Butterfly Wing ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Wing Scales

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for obtaining structural information of molecules in solution at low concentrations. While commercial SERS substrates are available, high costs prevent their wide-spread use in the medical field. One solution is to prepare requisite noble metal nanostructures exploiting natural nanostructures. As an example of biomimetic approaches, butterfly wing scales with their intricate nanostructures have been found to exhibit exquisite SERS activity when coated with silver. Selecting appropriate scales from particular butterfly species and depositing silver of certain thicknesses leads to significant SERS activity. For morphological observations we used scanning electron microscopes as well as a helium ion microscope, highly suitable for morphological characterization of poorly conducting samples. In this paper, we describe a protocol for carrying out SERS measurements based on butterfly wing scales and demonstrate its LOD with a common Raman reporter, rhodamine 6 G. We also emphasize what special care is necessary in such measurements. We also try to shed light on what makes scales work as SERS substrates by carefully modifying the original nanostructures. Such a study allows us to either use scales directly as a raw material for SERS substrate or provides an insight as to what nanostructures need to be recreated for synthetic SERS substrates.

scholarly journals Rapid uropathogen identification using surface enhanced Raman spectroscopy active filters

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%.

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

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.

scholarly journals Application of Doehlert Matrix for an Optimized Preparation of a Surface-Enhanced Raman Spectroscopy (SERS) Substrate Based on Silicon Nanowires for Ultrasensitive Detection of Rhodamine 6G

2019 ◽  
Vol 74 (2) ◽  
pp. 168-177 ◽  
Author(s):  
Awatef Ouhibi ◽  
Maroua Saadaoui ◽  
Nathalie Lorrain ◽  
Mohammed Guendouz ◽  
Noureddine Raouafi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nitrate ◽  
Silicon Nanowires ◽  
Rhodamine 6G ◽  
Surface Enhanced Raman Spectroscopy ◽  
Influential Factor ◽  
Metallic Surface ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

In this work, we combined a hierarchical nano-array effect of silicon nanowires (SiNWs) with a metallic surface of silver nanoparticles (AgNPs) to design a surface-enhanced Raman spectroscopy (SERS) scattering substrate for sensitive detection of Rhodamine 6G (R6G) which is a typical dye for fluorescence probes. The SiNWs were prepared by Metal-Assisted Chemical Etching (MACE) of n-Si (100) wafers. The Doehlert design methodology was used for planning the experiment and analyzing the experimental results. Thanks to this methodology, the R6G SERS response has been optimized by studying the effects of the silver nitrate concentration, silver nitrate and R6G immersion times and their interactions. The immersion time in R6G solution stands out as the most of influential factor on the SERS response.

Identification and Characterization of Artists' Red Dyes and Their Mixtures by Surface-Enhanced Raman Spectroscopy

2007 ◽  
Vol 61 (9) ◽  
pp. 994-1000 ◽  
Author(s):  
Alyson V. Whitney ◽  
Francesca Casadio ◽  
Richard P. Van Duyne
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Carminic Acid ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Lac Dye ◽  
Silver Island

Silver film over nanospheres (AgFONs) were successfully employed as surface-enhanced Raman spectroscopy (SERS) substrates to characterize several artists' red dyes including: alizarin, purpurin, carminic acid, cochineal, and lac dye. Spectra were collected on sample volumes (1 × 10−6 M or 15 ng/μL) similar to those that would be found in a museum setting and were found to be higher in resolution and consistency than those collected on silver island films (AgIFs). In fact, to the best of the authors' knowledge, this work presents the highest resolution spectrum of the artists' material cochineal to date. In order to determine an optimized SERS system for dye identification, experiments were conducted in which laser excitation wavelengths were matched with correlating AgFON localized surface plasmon resonance (LSPR) maxima. Enhancements of approximately two orders of magnitude were seen when resonance SERS conditions were met in comparison to non-resonance SERS conditions. Finally, because most samples collected in a museum contain multiple dyestuffs, AgFONs were employed to simultaneously identify individual dyes within several dye mixtures. These results indicate that AgFONs have great potential to be used to identify not only real artwork samples containing a single dye but also samples containing dyes mixtures.

scholarly journals Porous carbon nanowire array for surface-enhanced Raman spectroscopy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nan Chen ◽  
Ting-Hui Xiao ◽  
Zhenyi Luo ◽  
Yasutaka Kitahama ◽  
Kotaro Hiramatsu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Porous Carbon ◽  
Hot Spots ◽  
Strong Dependence ◽  
Nanowire Array ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Abstract Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for vibrational spectroscopy as it provides several orders of magnitude higher sensitivity than inherently weak spontaneous Raman scattering by exciting localized surface plasmon resonance (LSPR) on metal substrates. However, SERS can be unreliable for biomedical use since it sacrifices reproducibility, uniformity, biocompatibility, and durability due to its strong dependence on “hot spots”, large photothermal heat generation, and easy oxidization. Here, we demonstrate the design, fabrication, and use of a metal-free (i.e., LSPR-free), topologically tailored nanostructure composed of porous carbon nanowires in an array as a SERS substrate to overcome all these problems. Specifically, it offers not only high signal enhancement (~106) due to its strong broadband charge-transfer resonance, but also extraordinarily high reproducibility due to the absence of hot spots, high durability due to no oxidization, and high compatibility to biomolecules due to its fluorescence quenching capability.

Sign in / Sign up

Export Citation Format

Share Document