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On-Demand Electromagnetic Hotspot Generation in Surface Enhanced Raman Scattering Substrates via “Add-On” Plasmonic Patch
摘要： Electromagnetic hotspots at the interstices of plasmonic assemblies are recognized to be the most potent sites for surface enhanced Raman scattering (SERS). We demonstrate a novel “add-on” electromagnetic hotspot formation technique, which significantly improves the sensitivity of conventional SERS substrates comprised of individual plasmonic nanostructures. The novel approach demonstrated here involves the transfer of “plasmonic patch”, a transparent, flexible and conformal elastomeric film adsorbed with plasmonic nanostructures, onto a conventional SERS substrate. The addition of plasmonic patch onto conventional SERS substrate following the analyte capture results in the formation of electromagnetic hotspots and hence large SERS enhancement. The application of plasmonic patch improves the sensitivity and limit of detection of conventional SERS substrates by upto ~100-fold. The transfer of plasmonic patch also effectively transforms the SERS-inactive gold mirror to a highly SERS-active “particle-on-mirror” system. Furthermore, we demonstrate that the “add-on” technique can be effectively utilized for the vapor phase detection of explosives such as trinitrotoluene (TNT) using peptide recognition elements. We believe that the on-demand hotspot formation approach presented here represents a highly versatile and ubiquitously applicable technology readily expandable to any existing SERS substrate without employing complicated modification.
关键词： Trinitrotoluene (TNT),On-Demand Electromagnetic Hotspots,Surface Enhanced Raman Scattering (SERS),Plasmonic Patch,Plasmonic Nanostructures
更新于2025-09-11 14:15:04
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A Simple and Rapid Method to Produce SERS Substrates Using Au Nanoparticles Prepared by Laser Ablation and DVD Template
摘要： Simple and highly sensitive SERS substrates were produced using Au nanoparticles (AuNPs) prepared by laser ablation in water and available Digital Video Discs (DVDs). We used the simple ‘‘drop-cast’’ method to deposit AuNPs on the grating pattern surface of a DVD in place of the other methods such as electrochemical deposition, electrophoretic deposition and sputtering method which require some more equipment. AuNPs were proposed to be synthesized in water by laser ablation to form a nearly circular AuNP stain of small size on a DVD surface. The protecting polycarbonate layer of a DVD was removed from the DVD surface. The bare metallic DVD surface was rinsed carefully with ethanol and distilled water. The width of tracks on a DVD surface is around 300 nm and distance between them is around 450 nm. We prepared AuNPs by pulsed laser ablation of a gold piece in distilled water. The colloidal gold nanoparticles were deposited on DVD templates. We studied to produce an effective layer of AuNPs on DVD template for SERS substrates (AuNPs/DVD). The average SERS enhancement factor of the AuNPs/DVD SERS substrates is about 106. The SERS substrates can detect SERS spectra of Malachite Green and Amoxicillin at low concentrations of around 0.1–1 ppm.
关键词： Surface enhanced Raman scattering (SERS),digital video disc (DVD),laser ablation
更新于2025-09-11 14:15:04
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Gold nanoflowers grown in a porous Si/SiO2 matrix: the fabrication process and plasmonic properties
摘要： Highly branched metal nanostructures are of great interest for creating highly sensitive sensors of various molecules through the use of surface-enhanced Raman scattering. However, the method of manufacturing such nanostructures is often complex and difficult to reproduce. Herein, we report a simple, one-pot synthesis of flower-like gold nanostructures (AuNFs) in a porous Si/SiO2 matrix for potential surface enhanced Raman spectroscopy (SERS) applications. Templates covered with 500-nm diameter AuNFs with rough coral-like petals were obtained through a simple electroless reduction of gold(III) chloride salt in diluted hydrofluoric acid inside pores in the Si/SiO2 layer, which were obtained by swift heavy ion track technology. Detailed SERS analysis showed that single nanoflowers are capable of enhancing Raman signals and can be used as independent nanosensors. Having a few AuNFs in close proximity to each other enables more “hot spots” to be formed with an even greater increase in signal intensity. Using such substrates, reliable detection of 4-mercaptopyridine could be achieved down to 0.01 μM concentration. Finally, we theoretically demonstrate that the AuNFs are characterized by a wide-band plasmonic mode as well as by hot spots in the electromagnetic near-field distribution, which can result in a high enhancement factor for Raman scattering.
关键词： Surface-Enhanced Raman scattering,gold,nanoflowers,sensorics
更新于2025-09-11 14:15:04
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Manipulated interparticle gaps of silver nanoparticles by dendron-exfoliated reduced graphene oxide nanohybrids for SERS detection
摘要： We have successfully prepared a floating-typed surface-enhanced Raman scattering (SERS) substrate by the uniform nanoparticle arrays of silver nanoparticles (AgNPs) immobilized on the dendron-exfoliated reduced graphene oxide (rGO) nanosheets. These poly(urea/malonamide) dendrons were precisely synthesized, and then grafted on the dendron-exfoliated rGO nanosheets based on an efficient building block of dual functional 4-isocyanato-4′-(3,3-dimethyl-2,4-dioxo-azetidino)-diphenylmethane (IDD). By using dendron-rGO nanosheets as templates for hosting AgNPs, the particle size (D) and interparticle gap (W) of AgNPs could be manipulated by the incorporation of dendrons of various generations (0.5, 1.5, and 2.5 generations), evaluated by transmission electron microscopy. The results indicate that the nanohybrids with 1.5 generation-dendron exhibited stable, enormous, and linear-quantitative Raman enhancement in malachite green detection (1–100 ppm), due to the lowest W/D ratio (0.85 ± 0.60) and interparticle gap (7.60 ± 5.29 nm). The limit of detection (LOD) of malachite green is lower than 2.7 × 10?11 M (0.01 ppb). AgNPs@rGO-dendritic derivative nanohybrids as floating and flexible SERS substrates provide ultrasensitive and stable SERS detection in the solutions, which offers great potential for practical applications in detecting environmental pollutants.
关键词： Silver nanoparticles,Reduced graphene oxide nanosheets,Surface-enhanced Raman scattering detection,Dendritic polymers
更新于2025-09-11 14:15:04
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Two dimensional sinusoidal Ag nanograting exhibits polarization-independent surface-enhanced Raman spectroscopy and its surface plasmon polariton and localized surface plasmon coupling with Au nanospheres colloids
摘要： A reproducible surface‐enhanced Raman scattering (SERS) substrate based on two dimensional (2D) sinusoidal Ag nanograting is presented. This SERS substrate with large area can be easily fabricated by maskless laser interference photolithography. The potential SERS polarization‐independent performance of 2D sinusoidal Ag nanograting is deduced by finite difference time domain and demonstrated by SERS detection experiments. A double‐enhanced Raman scattering (DERS) substrate by coupling 2D sinusoidal Ag nanograting with Au nanospheres colloids is created. With the optimal DERS substrate, SERS enhancement factor can be 10 orders of magnitude as possible. The DERS substrate was fabricated and an extra SERS effect was proved by experiments. This DERS substrate will be fabricated in a microfluidics‐based sensor in the next work and used for in situ, real‐time, continuous monitoring of trace water soluble gas‐phase or airborne agents, such as trace explosives in air.
关键词： surface plasmon polaritons,surface enhanced Raman scattering,localized surface plasmons,two dimensional sinusoidal nanograting,polarization‐independent
更新于2025-09-10 09:29:36
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[ACS Symposium Series] Raman Spectroscopy in the Undergraduate Curriculum Volume 1305 || Research with Undergraduates at the Intersection of Chemistry and Art: Surface-Enhanced Raman Scattering Studies of Oil Paintings
摘要： Undergraduate students are provided increasingly the opportunity to explore Raman spectroscopy as a part of their physical and analytical chemistry courses. Here, we describe a new approach for engaging undergraduate students with Raman spectroscopy in the research lab setting. In particular, Wustholz at William & Mary and Svoboda at Colonial Williamsburg engage in productive collaboration wherein develop surface-enhanced Raman scattering (SERS)-based methods to identify fugitive pigments in art. In this chapter, we present several case studies that highlight the pedagogical journeys of student researchers working at the intersection of chemistry and art. We describe how this collaborative SERS research has led to discovery, innovation, and the professional development of undergraduates.
关键词： surface-enhanced Raman scattering,SERS,chemistry and art,undergraduate research,Raman spectroscopy,fugitive pigments
更新于2025-09-10 09:29:36
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Common Aspects Influencing the Translocation of SERS to Biomedicine
摘要： This review overviews the impact in biomedicine of surface enhanced Raman scattering motivated by the great potential we believe this technique has. We present the advantages and limitations of this technique relevant to bioanalysis in vitro and in vivo and how this technique goes beyond the state of the art of traditional analytical, labelling and healthcare diagnostic technologies.
关键词： early diagnosis,Biomedicine,nanoparticles,hybrid plasmonic platforms,bioanalytes,Surface-enhanced Raman Scattering (SERS),multiplexed bioanalysis,biosensors
更新于2025-09-10 09:29:36
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Fast sensing of imidacloprid residue in tea using surface-enhanced Raman scattering by comparative multivariate calibration
摘要： This study focused on the fabrication of a rapid, highly sensitive and inexpensive technique for the quantification of imidacloprid residue in green tea, based on surface-enhanced Raman scattering (SERS) using highly roughed surface flower shaped silver nanostructure (as SERS substrate) coupled with the chemometric algorithm. The basic principle of this method is imidacloprid yielded SERS signal after adsorption on Ag-NF under laser excitation by the electromagnetic enhancement and the intensity of the peak is proportional to the concentration ranging from 1.0×103 to 1.0×10-4 μg/mL. Among the models used, the GA-PLS (Genetic algorithm-partial least square) exhibited superiority to quantify imidacloprid residue in green tea. The model achieved Rp (correlation coefficient) of 0.9702 with RPD of 4.95 % in the test set and RSD for precision recorded up to 4.50 %. Therefore, the proposed sensor could be employed to quantify imidacloprid residue in green tea for the safeguarding of quality and human health.
关键词： Different PLS algorithm,Green tea,Flower-shaped silver nanostructure,Surface-enhanced Raman scattering,Imidacloprid residue
更新于2025-09-10 09:29:36
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Reusable surface-enhanced Raman substrates using microwave annealing
摘要： In this work, we report the fabrication of large-scale homogeneous surface-enhanced Raman scattering (SERS) substrates using a microwave annealing (MWA) process on Ag thin films on silicon, using a typical low-cost domestic microwave oven, avoiding the use of chemicals and stabilizing agents, or time-consuming and expensive approaches. We provide evidence that in 5–15 s, uniform and reproducible SERS substrates of several centimeter squares can be grown, providing a Raman signal enhancement of five orders of magnitude, for an incident Raman laser with an intensity as low as ~ 0.035 mW, against the characterization of Rhodamine 6G, which is a standard test molecule for SERS. Moreover, we tested the reusability of the fabricated MWA SERS substrates under conditions as tough as ultrasonic sonication in isopropyl alcohol and acetone for 15 min, respectively, and we demonstrate that our SERS substrates can be efficiently reused for more than six times after sonication, which is quite critical since it minimizes the cost of the procedure to minimum.
关键词： Surface-enhanced Raman scattering (SERS),Ag thin films,Rhodamine 6G (R6G),Reusable substrates,Microwave annealing (MWA)
更新于2025-09-10 09:29:36
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Copper-surrogated galvanic displacement of silver dendrite imprinted on flexible and transparent silk fibroin membrane as a SERS-active substrate and sub-dividable catalyst
摘要： By employing copper grid as a surrogate agent, we present a facial, reagent-free and cost-e?ective approach to imprint the exquisite silver dendroid nanostructures on ?exible silk ?broin membrane, which double roles as both optical enhancers and catalytic-active sites over many chemical reactions. Unlike the conventional rigid substrates, this hybrid Ag/protein composite exhibits many previous-inaccessible properties of ?exibility, transparency, biocompatibility, molecular permeability and optical manipulation. The galvanic displacement was facilitated by a high pressure uv-lamp illumination (365 nm), shortening the dendroid growth time to be within a few minutes. The resulting substrate was characterized by microscopic image, revealing a decent 3D Ag dendrite architecture and interpenetrated crystal network, which arguably enlarged the entire surface area and keenly regulated the optical/electric property of ?brillated protein ?lm. The underlying principle of copper-initiated silver reduction and growth of crystal structure was discoursed and veri?ed with in-situ spectroscopic interrogation. Moreover, our comprehensive study supports that sub-dividable substrate enables to perform catalytic reaction under a wide range of conditions. This exploration renders a thrust to expand biopolymeric membrane into a wide breadth of applications of bendable devices through chemical modi?cations, exhaustively and economically.
关键词： Galvanic replacement,Surface-enhanced Raman scattering,Sub-dividable catalyst,Silk membrane,Plasmon-driven photo-reduction
更新于2025-09-10 09:29:36