Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of t...Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.展开更多
Surface enhanced Raman scattering(SERS)is an efficient technique to detect low concentration molecules.In this work,periodical silicon nanowires(Si NWs)integrated with metal-insulator-metal(MIM)layers are employed as ...Surface enhanced Raman scattering(SERS)is an efficient technique to detect low concentration molecules.In this work,periodical silicon nanowires(Si NWs)integrated with metal-insulator-metal(MIM)layers are employed as SERS substrates.Laser interference lithography(LIL)combined with reactive ion etching(RIE)is used to fabricate large-area periodic nanostructures,followed by decorating the MIM layers.Compared to MIM disks array on Si surface,the SERS enhancement factor(EF)of the MIM structures on the Si NWs array can be increased up to 5 times,which is attributed to the enhanced electric field at the boundary of the MIM disks.Furthermore,high density of nanoparticles and nanogaps serving as hot spots on sidewall surfaces also contribute to the enhanced SERS signals.Via changing the thickness of the insulator layer,the plasmonic resonance can be tuned,which provides a new localized surface plasmon resonance(LSPR)characteristic for SERS applications.展开更多
Surface-enhanced Raman scattering(SERS) has been widely used as an effective technique for lowconcentration molecules detections in the past decades. This work proposes a rapid and accessible process to fabricate SERS...Surface-enhanced Raman scattering(SERS) has been widely used as an effective technique for lowconcentration molecules detections in the past decades. This work proposes a rapid and accessible process to fabricate SERS-active substrates with high uniformity and controllability based on two-step laser ablation. Laser beams directly ablate the surface of Si, concurrently creating microstructures and ejecting molten materials caused by the thermal effect that nucleate in ambient air. The nuclei grow into nanoparticles and deposit over the surface. These nanoparticles,together with microstructures, improve the light collection efficiency of the SERS-active substrates. Especially after Au thin film deposition, these nanoparticles can provide nanogaps as hotspots for SERS. By orthogonal experiment design,laser processing parameters for better performances are determined. Compared with substrates fabricated by single 1064 nm master oscillator power amplifier(MOPA) laser ablation, substrates ablated by the primary 1064 nm MOPA laser and secondary UV pulsed laser show more uniform nanoparticles’ deposition over the surface. The optimized largearea substrate has a SERS detection limit of 10^(-8)mol/L for 4-aminothiophenol(4-ATP), indicating the potential realworld applications for trace detection.展开更多
基金Project(10804101) supported by the National Natural Science Foundation of ChinaProject(2007CB815102) supported by the National Basic Research Program of ChinaProject(2007B08007) supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.
基金financial support from A*STAR,SERC 2014 Public Sector Research Funding (PSF) Grant (SERC Project No. 1421200080)
文摘Surface enhanced Raman scattering(SERS)is an efficient technique to detect low concentration molecules.In this work,periodical silicon nanowires(Si NWs)integrated with metal-insulator-metal(MIM)layers are employed as SERS substrates.Laser interference lithography(LIL)combined with reactive ion etching(RIE)is used to fabricate large-area periodic nanostructures,followed by decorating the MIM layers.Compared to MIM disks array on Si surface,the SERS enhancement factor(EF)of the MIM structures on the Si NWs array can be increased up to 5 times,which is attributed to the enhanced electric field at the boundary of the MIM disks.Furthermore,high density of nanoparticles and nanogaps serving as hot spots on sidewall surfaces also contribute to the enhanced SERS signals.Via changing the thickness of the insulator layer,the plasmonic resonance can be tuned,which provides a new localized surface plasmon resonance(LSPR)characteristic for SERS applications.
基金Project(2020H0006) supported by the Fujian Provincial Science and Technology ProgrammeChina+2 种基金Project(62175203) supported by the National Natural Science Foundation of ChinaProject(RD2020050301) supported by the Innovation Laboratory for Science and Technology of Energy Materials of Fujian Province Applied Research ProjectChina。
文摘Surface-enhanced Raman scattering(SERS) has been widely used as an effective technique for lowconcentration molecules detections in the past decades. This work proposes a rapid and accessible process to fabricate SERS-active substrates with high uniformity and controllability based on two-step laser ablation. Laser beams directly ablate the surface of Si, concurrently creating microstructures and ejecting molten materials caused by the thermal effect that nucleate in ambient air. The nuclei grow into nanoparticles and deposit over the surface. These nanoparticles,together with microstructures, improve the light collection efficiency of the SERS-active substrates. Especially after Au thin film deposition, these nanoparticles can provide nanogaps as hotspots for SERS. By orthogonal experiment design,laser processing parameters for better performances are determined. Compared with substrates fabricated by single 1064 nm master oscillator power amplifier(MOPA) laser ablation, substrates ablated by the primary 1064 nm MOPA laser and secondary UV pulsed laser show more uniform nanoparticles’ deposition over the surface. The optimized largearea substrate has a SERS detection limit of 10^(-8)mol/L for 4-aminothiophenol(4-ATP), indicating the potential realworld applications for trace detection.
