- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
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
-
Quantitative Determination of Urine Glucose: Combination of Laminar Flow in Microfluidic Chip with SERS Probe Technique
摘要： A surface-enhanced Raman scattering(SERS) sensing approach for urine glucose was developed based on the laminar flow technology in a cross-type microfluidic chip with SERS probes, 4-mercaptophenylboronic acid (MPBA) functionalized Ag nanoparticles. MPBA as the glucose receptor can identify and bind up with glucose at a molar ratio of 2:1, which can cause the aggregation of SERS probes at a certain position of the chip channel and further enhance the SERS signal of MPBA significantly. Thus, the quantitative SERS detection of glucose was achieved indirectly. No sample pretreatment and separation were needed in this method since the SERS detection was achieved in the gradient diffusion and molecular recognition processes between urine glucose and SERS probe in the laminar flow, which simplified the sample treatment procedures, saved detection time and made it feasible for clinic applications. This method shows a good linear relationship within human body’s normal physiological range and has high sensitivity and selectivity. The lowest detection concentration can reach 1.0 mg/dL.
关键词： Urine glucose,4-Mercaptophenylboronic acid,Microfluidic chip,Surface-enhanced Raman scattering(SERS)
更新于2025-09-10 09:29:36
-
A simple strategy to improve the sensitivity of probe molecules on SERS substrates
摘要： In this work, we report a simple strategy to improve the detection sensitivity as well as the spectral quality of probe molecules on surface-enhanced Raman scattering (SERS) substrates. On normal SERS substrates, due to the decreased absorption capacity and changes in the molecule orientations, SERS signals disappear when the analyte molecule concentrations reach a limit value. To solve this problem, the molecular template reagent (MTR) technique, a simple strategy based on SERS surface selection rules, is considered. By choosing the best MTR according to different samples, the effect of adjusting the molecular orientations of samples can be studied. In this process, 1-butanethiol, 1-hexanethiol, 1-octanethiol, 1-decanethiol, and 1-dodecanethiol, which are MTRs, are used to adjust the orientations of probe molecules under optimized conditions. The use of the MTR technique indicated that the limit of detection (LOD) of the probe molecules of p-aminobenzenethiol and 4-mercaptobenzoic acid on noble metal substrates showed an increase of one order of magnitude over the LOD of the pure probing molecule systems. Hence, the proposed method introduces a way to detect the molecules with an improved sensitivity at extremely low concentrations. The study corresponds to a proof-of-concept study of MTR-assisted SERS for SERS-based applications in ultrasensitive analyses.
关键词： Surface-enhanced Raman scattering (SERS),Molecular template reagent (MTR),Ultrasensitive analyses,SERS substrates
更新于2025-09-09 09:28:46
-
Total Aqueous Synthesis of Au@Cu <sub/>2?</sub><i> <sub/>x</sub></i> S Core–Shell Nanoparticles for In Vitro and In Vivo SERS/PA Imaging‐Guided Photothermal Cancer Therapy
摘要： Both accurate tumor navigation and nanostructures with high photothermal (PT) conversion efficiency are important but remain challenging to achieve in current biomedical applications. This study reports an anion exchange-based facile and green approach for synthesizing Au@Cu2?xS core–shell nanoparticles (NPs) in an aqueous system. In addition to the PT effect of the suggested NPs, the surface-enhanced Raman scattering (SERS) is also significantly improved due to the tailored localized surface plasmon resonance coupling between the Au metal core and the Cu2?xS semiconductor shell. Using an epitaxial strategy, Au@Cu2O NPs are first obtained by the in situ reduction of cupric hydroxide on a cresyl violet acetate-coated Au core; then, Au@Cu2?xS NPs are obtained via anion exchange between the S2? and Cu2O shell. Both the Cu/S atomic ratio and the Cu2?xS shell thickness can be adjusted conveniently. Hence, the ideal integration of the plasmonic Au core and Cu2?xS shell into a single unit is conducive not only to highly efficient PT conversion but also to the construction of a SERS-based navigator. This new type of SERS-guided NP, with enhanced photoacoustic signals, is an important candidate for both accurate tumor navigation and nondestructive PT treatment guided in vivo by two modes of optical imaging.
关键词： navigation treatment,photothermal therapy (PTT),Au@Cu2?xS core–shell nanoparticles (NPs),plasmonic enhancement,surface-enhanced Raman scattering (SERS)
更新于2025-09-09 09:28:46
-
Metal-organic frameworks as SERS substrates with high tailorability
摘要： Surface enhanced Raman scattering (SERS) is a widely used analytical technique for detecting trace-level molecules based on an indispensable SERS substrate. SERS substrates with high tailorability are assumed to be attractive and desirable for SERS detection, because the substrates match the need for the selective detection of different species. Nevertheless, the rational design of such SERS substrates is rather challenging for both noble-metal and semiconductor substrates. Herein, expanding beyond conventional SERS substrates, we demonstrate that metal-organic framework (MOF) materials can serve as a type of SERS substrate with molecular selectivity, which are rarely realized for SERS detection without any special pretreatment. A salient structural characteristic of MOF-based SERS substrates benefiting the SERS selectivity is their high tailorability. By controlling the metal centers, organic ligands, and framework topologies of our MOF-based SERS substrates, we show that the electronic band structures of MOF-based SERS substrate can be purposively manipulated to match those of the target analytes, thus resulting in different detectable species. Going further, the SERS enhancement factors (EFs) of the MOF-based SERS substrates can be greatly enhanced to as high as 106 with a low detection limit of 10-8 M by pore-structure optimization and surface modification, which is comparable to the EFs of noble metals without “hot spots” and recently-reported semiconductors. This selective enhancement is interpreted as being due to the controllable combination of several resonances, such as the charge-transfer, interband and molecule resonances, together with the ground-state charge-transfer interactions. Our study opens a new venue for the development of SERS substrates with high-design flexibility, which is especially important for selective SERS detection towards specific analytes.
关键词： Surface enhanced Raman scattering (SERS),tailorability,charge-transfer,molecular selectivity,interband and molecule resonances,enhancement factors (EFs),metal-organic framework (MOF),ground-state charge-transfer interactions,SERS substrates
更新于2025-09-04 15:30:14
-
Designing surface-enhanced Raman scattering (SERS) platforms beyond hotspot engineering: emerging opportunities in analyte manipulations and hybrid materials
摘要： Surface-enhanced Raman scattering (SERS) is a molecule-specific spectroscopic technique with diverse applications in (bio)chemistry, clinical diagnosis and toxin sensing. While hotspot engineering has expedited SERS development, it is still challenging to detect molecules with no specific affinity to plasmonic surfaces. With the aim of improving detection performances, we venture beyond hotspot engineering in this tutorial review and focus on emerging material design strategies to capture and confine analytes near SERS-active surfaces as well as various promising hybrid SERS platforms. We outline five major approaches to enhance SERS performance: (1) enlarging Raman scattering cross-sections of non-resonant molecules via chemical coupling reactions; (2) targeted chemical capturing of analytes through surface-grafted agents to localize them on plasmonic surfaces; (3) physically confining liquid analytes on non-wetting SERS-active surfaces and (4) confining gaseous analytes using porous materials over SERS hotspots; (5) synergizing conventional metal-based SERS platforms with functional materials such as graphene, semiconducting materials, and piezoelectric polymers. These approaches can be integrated with engineered hotspots as a multifaceted strategy to further boost SERS sensitivities that are unachievable using hotspot engineering alone. Finally, we highlight current challenges in this research area and suggest new research directions towards efficient SERS designs critical for real-world applications.
关键词： non-wetting surfaces,porous materials,Surface-enhanced Raman scattering,SERS,plasmonic surfaces,chemical coupling,hotspot engineering,semiconductors,piezoelectric polymers,analyte manipulation,hybrid materials,graphene
更新于2025-09-04 15:30:14