- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Broad-Spectrum Tunable Photoluminescent Material Based on Cascade Fluorescence Resonance Energy Transfer between Three Fluorophores Encapsulated within the Self-Assembled Surfactant Systems
摘要： A broad spectrum tunable photoluminescent material with dual encryption based on a two-step Fluorescence Resonance Energy Transfer (FRET) between Pyrene (Py), Coumarin480 (Cou480) and Rhodamine6G (R6G) in micelles of SDS and bmimDS is presented. The phenomenon is achievable due to the encapsulation of the fluorophores within these micelles. The transfer of energy as FRET between the pair Py and Cou480 showed ON at 336 nm and OFF at 402 nm in contrast to the FRET observed between the pair Cou480 and R6G that showed ON at 402nm and OFF at 336 nm. However, the transfer of energy as FRET occurs from Py to R6G in the presence of Cou480 when excited at 336 nm, thereby making it a chain of three fluorophores with Cou480 acting as a relay fluorophore receiving energy from Py and transferring it to R6G. The different FRET scenarios between the three fluorophores in micelles provide a window for the generation of a matrix of colors, which occupies a significant 2D area in the chromaticity diagram, having potential applications in security printing. The different fluorophoric ratios generate different colors based on their individual photonic emissions and the FRET processes taking place between them. Writing tests were carried out using varied ratios of the fluorophores in the micellar systems producing different colored outputs under the UV light with insignificant visibility under the white light. We envision that this as-discovered three fluorophoric FRET system could form the basis for the future development of multi-FRET light-harvesting devices and anti-counterfeiting security inks based on much simpler non-covalent interaction aided encapsulation of the fluorophores within the self-assembled soft systems.
关键词： micelles,security printing,Rhodamine6G (R6G),SDS,Pyrene (Py),Coumarin480 (Cou480),bmimDS,Fluorescence Resonance Energy Transfer (FRET),photoluminescent material
更新于2025-11-19 16:46:39
-
Silver Nanostructures on Graphene Oxide as the Substrate for Surface-Enhanced Raman Scattering (SERS)
摘要： Nanosized surface-enhanced Raman scattering (SERS) substrates fabricated by the controlled growth of metal nanostructures on water-dispersed two-dimensional nanomaterials can open a new avenue for SERS analysis of liquid samples in biological fields. In this work, regular and uniform Ag nanostructures were grown on the surface of graphene oxide (GO) through a microwave-assisted hydrothermal method. Polyamidoamine (PAMAM) dendrimers were assembled on the surface of GO to form GO/PAMAM templates for growing Ag nanostructures, which are primarily comprised of Ag dimers and trimers. The prepared Ag/GO nanocomposites are highly dispersed and stable in aqueous solution and may be used as substrates for enhanced Raman detection of rhodamine 6 G (R6G) in aqueous solution. This special substrate provides high-performance SERS and suppresses R6G fluorescence in aqueous solution and is promising as a nanosized material for the enhanced Raman detection of liquid samples in biological diagnostics.
关键词： graphene oxide (GO),Surface-enhanced Raman scattering (SERS),polyamidoamine (PAMAM) dendrimers,transmission electron microscopy (TEM),Fourier transform infrared (FTIR) spectroscopy,rhodamine 6G (R6G)
更新于2025-09-23 15:23:52
-
Plasmonic Molybdenum Tungsten Oxide Hybrid with Surface-Enhanced Raman Scattering Comparable to that of Noble Metals
摘要： The Surface-enhanced Raman Scattering (SERS) research is in full swing owing to its high sensitivity and high selectivity, however, the substrate with a superexcellent performance for SERS is largely confined to noble metals (Au and Ag, etc.). Although the SERS active substrate has been extended to semiconductor and transition metal, it is frustrating that their sensitivity is insufficient for widespread practical application. Here we report the plasmonic molybdenum tungsten oxide hybrid (MWO) nanomaterials (NMs) which can be used as a high-performance substrate with noble metal-comparable SERS. MWO NMs can achieve the trace detection of rhodamine 6G (R6G), basic fuchsin (BF), and oil red O (ORO). The detection limit concentration for R6G is 10-8 M with the maximum enhancement factor is up to 6.09×107. The superexcellent SERS performance was put down to the cooperative enhancement effect of electromagnetic enhancement mechanism (EM) and the charge transfer mechanism (CT). Moreover, in the proposed system, the EM and CT contribution was distinguished by employing the PVP, which serves as a barrier layer to prevent the CT process from MWO NMs to R6G. This remarkable MWO NMs can be obtained with a facile method and this research shows a new insight on the non-noble metal-based SERS substrate.
关键词： Molybdenum tungsten oxide hybrid,R6G,Noble metal-comparable,SERS,Plasmonic
更新于2025-09-19 17:13:59
-
Advanced Design of Microfluidic Chip Based on SPP-LSP Plasmonic Coupling for SERS Detection with High Sensitivity and Reliability
摘要： In this work, we propose the preparation and investigation of advanced microfluidic Surface-enhanced Raman spectroscopy (SERS) chip with the design, allowing high SERS enhancement and analysis reproducibility. Proposed chip implements the creation of periodical metal structure (grating) inside the microfluidic chip and further immobilization of gold multibranched nanoparticles (AuMs) with shaped edges on the grating surface. Such approach allows achieving plasmonic coupling between the surface plasmon polariton wave, excited on the Au grating, and localized surface plasmon, excited on sharped edges of AuMs. As a result, the high enhancement of electric field in the space between AuMs was achieved, which results in the high SERS enhancement factor, confirmed by both, theoretical calculation and experimental measurements with typical SERS analyte – R6G. In particular, vanishingly small concentration of R6G is possible to detect using the proposed plasmonic coupling, which sensitivity significantly exceeds previously reported limits in the case of microfluidic SERS measurements. We also observed the dependency of SERS intensity on the microfluidic flow rate and demonstrated the perfect reliability of the SERS signal, measured in the microfluidic regimes under the constant flow rate.
关键词： SERS,plasmonic coupling,gold multibranched nanoparticles,microfluidic chip,R6G,Surface-enhanced Raman spectroscopy
更新于2025-09-11 14:15:04
-
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
-
The synthesis of Ag-coated tetrapod gold nanostars and the improvement of surface-enhanced Raman scattering
摘要： In this work, the novel tetrapod gold nanostars with four specific numbers of sharp tips were synthesized with good uniformity, high yield and chemical stability. The size of tetrapod gold nanostars has been increased effectively by increasing the amount of HAuCl4 or DEA added to the reaction solution, and the corresponding in-plane localized surface plasmon resonance (LSPR) band can shift from 700 to 1100 nm. In order to combine the advantages of different metals, the Ag-coated tetrapod gold nanostars were prepared with different Ag coating thicknesses by increasing the volume of AgNO3. With the increase of Ag coating thickness, the morphology of the nanoparticles has changed from gold nanostars with four sharp tips to bimetallic cuboids with four sharp tips and finally to core-shell cuboids completely. The surface-enhanced Raman scattering (SERS) activity of Ag-coated tetrapod gold nanostars has also been improved with the different Ag coating thicknesses. Combined the tip effect and the enhancement effect of Ag, the SERS activity has the strongest enhancement when the four sharp tips of tetrapod gold nanostars are not completely coated by the Ag layer but still exposed to the outsides. For tetrapod gold nanostars with larger size to grow Ag-coated tetrapod gold nanostars, the bimetallic cuboids with four sharp tips nanostructure have the biggest SERS enhancement factor (EF) of 1.73×106 for Rhodamine 6G (R6G), making it an ideal candidate in SERS-based sensing application.
关键词： R6G,Au-Ag bimetallic cuboids,SERS,Tetrapod gold nanostars,Silver coating
更新于2025-09-10 09:29:36