The effect of solvent on surface enhanced Raman scattering [SERS) of colloidal silver has been studied. Experiments show that the intensity of SERS is related to the polarity and molecular constitution of the solvent....The effect of solvent on surface enhanced Raman scattering [SERS) of colloidal silver has been studied. Experiments show that the intensity of SERS is related to the polarity and molecular constitution of the solvent. The influence of solvent is due to the change of the adsorption quantity and adsorption intensity.展开更多
Multifunctional TiO2/Ag composite nanowires are fabricated with a hydrothermal method by precipitating Ag nanoparticles (NPs) on the surfaces of TiO2 nanowires. This hierarchical one-dimensional (1D) nanostructure...Multifunctional TiO2/Ag composite nanowires are fabricated with a hydrothermal method by precipitating Ag nanoparticles (NPs) on the surfaces of TiO2 nanowires. This hierarchical one-dimensional (1D) nanostructure can be used as a surface enhanced Raman scattering (SERS) substrate with high sensitivity, for detecting the rhodamine 6G (R6G) in a wide range of low concentrations (from 1 × 10 6 M to 1 × 10-12 M). In addition, the substrate can be self-cleaned under the irradiation of ultraviolet (UV) light due to the superior photocatalytic capacity of the TiO2/Ag composite nanostructure, making the recycled use of SERS substrates closer to reality. With both the evident SERS performance and high efficiency of photocatalytic capacity, such TiOz/Ag composite nanowires demonstrate considerable potential in the chemical sensing of organic pollutants.展开更多
Surface enhanced Raman scattering (SERS) spectroscopy was first utilized to study the photo-orientation behaviour of the photoreactive groups on a novel photo-alignment film surface and elucidate the generation mechan...Surface enhanced Raman scattering (SERS) spectroscopy was first utilized to study the photo-orientation behaviour of the photoreactive groups on a novel photo-alignment film surface and elucidate the generation mechanism of pretilt angle. The novel photo-alignment film was prepared by spin-coating a solution of ladderlike polysiloxane (LPS) bearing dual photoreactive group on an ITO surface and by irradiation with linear-polarized ultraviolet (LPUV) light A Si—H terminal compound (M) containing an identical photosensitive part has been used to fabricate a model film for SERS investigation.展开更多
In this paper,we report the study of surface-enhanced Raman Scattering of C_(60)films on roughed Ag,Cu and glass surface.The experiment results indicate that the C_(60)films on Ag substrate possess large enhance effec...In this paper,we report the study of surface-enhanced Raman Scattering of C_(60)films on roughed Ag,Cu and glass surface.The experiment results indicate that the C_(60)films on Ag substrate possess large enhance effect.An explanation of the enhancement with roughed glass surface is proposed based on waveguide Raman Scattering.展开更多
Single-atom nanozymes(SAzymes)are emerging as promising alternatives to mimic natural enzyme,which is due to high atomic utilization efficiency,well-defined geometric,and unique electronic structure.Herein,Fe single a...Single-atom nanozymes(SAzymes)are emerging as promising alternatives to mimic natural enzyme,which is due to high atomic utilization efficiency,well-defined geometric,and unique electronic structure.Herein,Fe single atoms supported on Ti_(3)C_(2)T_(x)(Fe-SA/Ti_(3)C_(2)T_(x))with intrinsic peroxidase activity is developed,further constructing a sensitive Raman sensor array for sensing of five antioxidants.Fe-SA/Ti_(3)C_(2)T_(x)shows excellent peroxidase-like performance in catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)with colorimetric reactions.X-ray adsorption fine structure(XAFS)reveals that the electron transport between the Ti_(3)C_(2)T_(x)and Fe atoms occurs along Fe-O-Ti ligands,meanwhile the density functional theory(DFT)calculations confirm the spontaneous dissociation of H_(2)O_(2)and the formation of OH radicals.Furthermore,the peroxidase-like Fe-SA/Ti_(3)C_(2)T_(x)was used as surface enhanced Raman scattering(SERS)substrate of oxidized TMB(TMB+)and achieved satisfied signal amplification performance.Using the blocking effects of free radical reactions,one-off identification of 5 antioxidants,including ascorbic acid(AA),uric acid(UA),glutathione(GSH),melatonin(Mel),and tea polyphenols(TPP),could be realized with this high identifiable catalytic property.This principle could realize 100%distinguish accuracy combined with linear discriminant analysis(LDA)and heat map data analysis.A wide detection concentration ranges from 10^(-8)to 10^(-3)M for five antioxidants was also achieved.展开更多
The surface-enhanced Raman spectroscopy(SERS)is a technique for the detection of analytes on the surface with an ultrahigh sensitivity down to the atomic-scale,yet the fabrication of SERS materials such as nanoparticl...The surface-enhanced Raman spectroscopy(SERS)is a technique for the detection of analytes on the surface with an ultrahigh sensitivity down to the atomic-scale,yet the fabrication of SERS materials such as nanoparticles or arrays of coinage metals often involve multiple complex steps with the high cost and pollution,largely limiting the application of SERS.Here,we report a complex hierarchical metallic glassy(MG)nanostructure by simply replicating the surface microstructure of butterfly wings through vapor deposition technique.The MG nanostructure displays an excellent SERS effect and moreover,a superhydrophobicity and self-cleaning behavior.The SERS effect of the MG nanostructure is attributed to the intrinsic nanoscale structural heterogeneities on the MG surface,which provides a large number of hotspots for the localized electromagnetic field enhancement affirmed by the finite-difference time-domain(FDTD)simulation.Our works show that the MG could be a new potential SERS material with low cost and good durability,well extending the functional application of this kind of material.展开更多
Gold nanorods with aspect ratios of from 1 (particles) to 31.6 were synthesized by the seed-mediated method and packed in a highly ordered structure on a large scale on silicon substrates through capillary force ind...Gold nanorods with aspect ratios of from 1 (particles) to 31.6 were synthesized by the seed-mediated method and packed in a highly ordered structure on a large scale on silicon substrates through capillary force induced self-assembly behaviour during solvent evaporation. The gold nanorod surface exhibits a strong enhancing effect on Raman scattering spectroscopy. The enhancement of Raman scattering for two model molecules (2-naphthalenethiol and rhodamine 6C) is about 5-6 orders of magnitude. By changing the aspect ratio of the Au nanorods, we found that the enhancement factors decreased with the increase of aspect ratios. The observed Raman scattering enhancement is strong and should be ascribed to the surface plasmon coupling between closely packed nanorods, which may result in huge local electromagnetic field enhancements in those confined junctions.展开更多
Aggregation of metal nanoparticles plays an important role in surface enhanced Raman scattering(SERS). Here, a strategy of dynamically aggregating/releasing gold nanoparticles is demonstrated using a gold-nanofilm-coa...Aggregation of metal nanoparticles plays an important role in surface enhanced Raman scattering(SERS). Here, a strategy of dynamically aggregating/releasing gold nanoparticles is demonstrated using a gold-nanofilm-coated nanofiber, with the assistance of enhanced optical force and plasmonic photothermal effect. Strong SERS signals of rhodamine 6 G are achieved at the hotspots formed in the inter-particle and film-particle nanogaps. The proposed SERS substrate was demonstrated to have a sensitivity of 10-12 M, reliable reproducibility, and good stability.展开更多
Plasmon coupling is an essential strategy to realize strong local electromagnetic(EM)field which is crucial for high-performance plasmonic devices.In this work,multiple plasmon couplings are demonstrated in three-dime...Plasmon coupling is an essential strategy to realize strong local electromagnetic(EM)field which is crucial for high-performance plasmonic devices.In this work,multiple plasmon couplings are demonstrated in three-dimensional(3D)hybrid plasmonic systems composed of polydimethylsiloxane-supported ordered silver nanocone(AgNC)arrays decorated with high-density gold nanoparticles(AuNPs)which are fabricated by a template-assisted physical vapor deposition process.Strong interparticle coupling,particle-film coupling,inter-cone coupling,and particle-cone coupling are revealed by numerical simulations in such composite nanostructures,which produce intense and high-density EM hot spots,boosting highly sensitive and reproducible surface enhanced Raman scattering(SERS)detection with an enhancement factor of-1.74×10^(8).Furthermore,a linear correlation between logarithmic Raman intensity and logarithmic concentration of probe molecules is observed in a large concentration range.These results offer new ideas to develop novel plasmonic devices,and provide alternative strategy to realize flexible and high-performance SERS sensors for trace molecule detection and quantitative analysis.展开更多
Contamination by accidental cutaneous contact with the commercial products and the air pol-hutants raised a considerable health and safety issue.This study aimed to trace the dynamics of the 20 nm gold nanopartide(GNP...Contamination by accidental cutaneous contact with the commercial products and the air pol-hutants raised a considerable health and safety issue.This study aimed to trace the dynamics of the 20 nm gold nanopartide(GNP)penetration and accumulation in rat skin tissues using a surface-enhanced Raman scattering(SERS)techmique.After the topical application of GNPs on rat skin surface,the SERS spectra were recorded for every 15 pum to an overall depth of 75 pum from skin surface for 150 min.The processes of GNP penetration in rat skin were accompanied by aggregation of GNPs,which affected SERS spectra.The results revealed that 20 nm GNPs can penetrate through stratum corneum layer,viable epidermis layer,and then into dermis layer.This study demonstrated for the first time the potential of SERS spectroscopy to monitor the penetration and accumulation of GNPs in rat skin.展开更多
An effective surface enhanced Raman scattering(SERS) substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface i...An effective surface enhanced Raman scattering(SERS) substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface in order to create numerous "hot spots". The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.展开更多
A fabrication process based on the self-assembling polystyrene spheres is proposed to obtain hole arrayed metal-insulator-metal (HA-MIM) structure for surface enhanced Raman scattering (SERS). The localized field ...A fabrication process based on the self-assembling polystyrene spheres is proposed to obtain hole arrayed metal-insulator-metal (HA-MIM) structure for surface enhanced Raman scattering (SERS). The localized field enhancement aroused by the gap resonance in the HA-MIM structure is analyzed by finite-different time domain (FDTD) method. With reference to the theory result, the structure is experimentally fabricated and the Raman scattering spectrum of rhodamine 6G (R6G) is measured by a miniaturized Raman spectrometer. The results shows that the enhancement factor is 3.85 times higher than the control sample with single layered metal hole array. The fabrication process to obtain the HA-MIM SERS substrate is reproducible, fast, large area and low cost.展开更多
A combined Ag nanoparticle with an insulating or conductive layer structure has been designed tor molecular detection using surface enhanced Raman scattering microscopy. Optical absorption studies revealed localized s...A combined Ag nanoparticle with an insulating or conductive layer structure has been designed tor molecular detection using surface enhanced Raman scattering microscopy. Optical absorption studies revealed localized surface plasmon resonance, which shows regular red shift with increasing environmental dielectric constant. With the combined structure of surface enhanced Raman scattering substrates and rhodamine 6C as a test molecule, the results in this paper show that the absorption has a linear relationship with the local electromagnetic field for insulating substrates, and the electrical property of the substrate has a non-negligible effect on the intensity of the local electromagnetic field and hence the Raman enhancement.展开更多
Surface Plasmon Resonance (SPR) is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber applicat...Surface Plasmon Resonance (SPR) is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering (SERS) probe. Long-period fiber gratings are fabricated on single mode polymer optical fiber (POF) with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.展开更多
Coherent anti-Stokes Raman scattering spectroscopy(CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels,while...Coherent anti-Stokes Raman scattering spectroscopy(CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels,while the enhancement factor for surface plasmon resonances(SPR) are extensively used to increase the local field close to the oscillators and which can obtain high enhancement. In this work, we investigate the enhancement factor of our structure for surface-enhanced coherent anti-Stokes Raman scattering. The absorption spectrum of the structure has been studied, a wide range of absorption has been realized. The enhancement can be as high as 10^(16) over standard CARS. Our design is very useful for improving the enhancement factor of surface-enhanced coherent anti-Stokes Raman scattering.展开更多
Creatinine level in urine is an important biomarker for renal function diseases,such as renal failure,glomerulonephritis,and chronic nephritis.The Au@MIL-101(Fe)was prepared by in situ growth of Au nanoparticles in MI...Creatinine level in urine is an important biomarker for renal function diseases,such as renal failure,glomerulonephritis,and chronic nephritis.The Au@MIL-101(Fe)was prepared by in situ growth of Au nanoparticles in MIL-101(Fe)as a selective SERS substrate.The Au@MIL-101(Fe)offers the great local surface plasmon resonance(SPR)effect due to gold nanoparticles aggre-gation inside metal-organic frameworks.The framework structure could enrich trace target samples and drag them into SPR hot spots.The optimal Au@MIL-101(Fe)composite substrate is used for analyzing creatinine in urine and the limit of detection is down to 0.1μmol/L and a linear relationship is ranging from 1μmol/L to 100μmol/L.展开更多
Metal foils for Raman scattering were prepared by HNO_3 etching method. These foils werefound to exhibit a strong SERS effect and excellent thermal stability. SERS spectra of cystaminehave been taken to illustrate the...Metal foils for Raman scattering were prepared by HNO_3 etching method. These foils werefound to exhibit a strong SERS effect and excellent thermal stability. SERS spectra of cystaminehave been taken to illustrate the usefulness of this sample preparation method in the studies ofchemisorption. The ring opening reactions of an epoxy compound have been observed on the topof chemisorbed cystamine on silver foils.展开更多
Polystyrene films were adsorbed onto a silver surface from dichloromethane solutions with concentrations of 0.1 to 12 wt%, and then studied by the surface enhanced Raman technique. A critical concentration for coil in...Polystyrene films were adsorbed onto a silver surface from dichloromethane solutions with concentrations of 0.1 to 12 wt%, and then studied by the surface enhanced Raman technique. A critical concentration for coil interpenetration was observed.展开更多
When colloidal silver particles were chemically deposited onto polymer film as an over-coating layer, surface-enhanced Raman scattering (SERS) spectra could be collected for the surface analysis. SERS measurements of ...When colloidal silver particles were chemically deposited onto polymer film as an over-coating layer, surface-enhanced Raman scattering (SERS) spectra could be collected for the surface analysis. SERS measurements of liquid crystal film were successfully performed without disturbing the surface morphology.展开更多
Significant amplification of surface enhanced Raman scattering(SERS)signals can be achieved mainly by the electric field enhancement in metal core-shell nanostructures,and the enhanced magnetic field is rarely studied...Significant amplification of surface enhanced Raman scattering(SERS)signals can be achieved mainly by the electric field enhancement in metal core-shell nanostructures,and the enhanced magnetic field is rarely studied.In this study,we prepared multi-gap Au/AgAu core-shell hybrid nanostructures by using gold nanocup as the core.The overgrowth processes to grow one,two,and three layers of AgAu hybrid nanoshells can produce Au/AgAu^(1),Au/AgAu^(2),and Au/AgAu^(3) heteronanostructures.The strong plasmon coupling between the core and shell leads to significant electromagnetic field enhancement.Under the synergistic effect of electromagnetic plasmon resonance and plasmon coupling,Au/AgAu core-shell hybrid nanostructures exhibit excellent SERS signals.We also investigate the effect of the interstitial position of the rhodamine B(RhB)molecule on Raman enhancement in Au/AgAu~3 heteronanostructures.This study can provide new ideas for the synthesis of multi-gap Raman signal amplifiers based on magnetic plasmon coupling.展开更多
文摘The effect of solvent on surface enhanced Raman scattering [SERS) of colloidal silver has been studied. Experiments show that the intensity of SERS is related to the polarity and molecular constitution of the solvent. The influence of solvent is due to the change of the adsorption quantity and adsorption intensity.
基金Project supported by the National Natural Science Foundation of China (Grant No.10705056)the "985 Project" (Grant No.98507-010009)+2 种基金the "211 Project" of Ministry of Education of Chinathe Pilot Project of Comprehensive Reform for the Specialty of Applied Physics of Minzu University of Chinathe Undergraduate Research Training Program of Minzu University of China (Grant Nos.GCCX 2012110007 and 2012110008)
文摘Multifunctional TiO2/Ag composite nanowires are fabricated with a hydrothermal method by precipitating Ag nanoparticles (NPs) on the surfaces of TiO2 nanowires. This hierarchical one-dimensional (1D) nanostructure can be used as a surface enhanced Raman scattering (SERS) substrate with high sensitivity, for detecting the rhodamine 6G (R6G) in a wide range of low concentrations (from 1 × 10 6 M to 1 × 10-12 M). In addition, the substrate can be self-cleaned under the irradiation of ultraviolet (UV) light due to the superior photocatalytic capacity of the TiO2/Ag composite nanostructure, making the recycled use of SERS substrates closer to reality. With both the evident SERS performance and high efficiency of photocatalytic capacity, such TiOz/Ag composite nanowires demonstrate considerable potential in the chemical sensing of organic pollutants.
基金This work was supported by the National Natural Science Foundation of China (No. 50073028, 29974036, 20174047).
文摘Surface enhanced Raman scattering (SERS) spectroscopy was first utilized to study the photo-orientation behaviour of the photoreactive groups on a novel photo-alignment film surface and elucidate the generation mechanism of pretilt angle. The novel photo-alignment film was prepared by spin-coating a solution of ladderlike polysiloxane (LPS) bearing dual photoreactive group on an ITO surface and by irradiation with linear-polarized ultraviolet (LPUV) light A Si—H terminal compound (M) containing an identical photosensitive part has been used to fabricate a model film for SERS investigation.
文摘In this paper,we report the study of surface-enhanced Raman Scattering of C_(60)films on roughed Ag,Cu and glass surface.The experiment results indicate that the C_(60)films on Ag substrate possess large enhance effect.An explanation of the enhancement with roughed glass surface is proposed based on waveguide Raman Scattering.
基金This work was supported by the National Natural Science Foundation of China(Nos.51872011,51902011,and 22005013)Beijing Natural Science Foundation(No.2212018)+1 种基金Beijing Institute of Technology Research Fund Program for Young Scholars(No.2022CX01011)Chinese Academy of Sciences。
文摘Single-atom nanozymes(SAzymes)are emerging as promising alternatives to mimic natural enzyme,which is due to high atomic utilization efficiency,well-defined geometric,and unique electronic structure.Herein,Fe single atoms supported on Ti_(3)C_(2)T_(x)(Fe-SA/Ti_(3)C_(2)T_(x))with intrinsic peroxidase activity is developed,further constructing a sensitive Raman sensor array for sensing of five antioxidants.Fe-SA/Ti_(3)C_(2)T_(x)shows excellent peroxidase-like performance in catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)with colorimetric reactions.X-ray adsorption fine structure(XAFS)reveals that the electron transport between the Ti_(3)C_(2)T_(x)and Fe atoms occurs along Fe-O-Ti ligands,meanwhile the density functional theory(DFT)calculations confirm the spontaneous dissociation of H_(2)O_(2)and the formation of OH radicals.Furthermore,the peroxidase-like Fe-SA/Ti_(3)C_(2)T_(x)was used as surface enhanced Raman scattering(SERS)substrate of oxidized TMB(TMB+)and achieved satisfied signal amplification performance.Using the blocking effects of free radical reactions,one-off identification of 5 antioxidants,including ascorbic acid(AA),uric acid(UA),glutathione(GSH),melatonin(Mel),and tea polyphenols(TPP),could be realized with this high identifiable catalytic property.This principle could realize 100%distinguish accuracy combined with linear discriminant analysis(LDA)and heat map data analysis.A wide detection concentration ranges from 10^(-8)to 10^(-3)M for five antioxidants was also achieved.
基金The authors would like to thank the support of the National Natural Science Foundation of China(Nos.51822107,51671121,51761135125,and 61888102)the National Key Research and Development Program(No.2018YFA0703603)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB07030200 and XDB30000000)We appreciate Professor Di Zhang’s deep discussions on the usage of bio-templates.The authors also thank Ruhao Pan and Xianzhong Yang for discussions on collecting Raman spectra,Mo Han Wang for the measurement of UV–vis absorption spectra and Kun Chen for the dielectric coefficient measurement.
文摘The surface-enhanced Raman spectroscopy(SERS)is a technique for the detection of analytes on the surface with an ultrahigh sensitivity down to the atomic-scale,yet the fabrication of SERS materials such as nanoparticles or arrays of coinage metals often involve multiple complex steps with the high cost and pollution,largely limiting the application of SERS.Here,we report a complex hierarchical metallic glassy(MG)nanostructure by simply replicating the surface microstructure of butterfly wings through vapor deposition technique.The MG nanostructure displays an excellent SERS effect and moreover,a superhydrophobicity and self-cleaning behavior.The SERS effect of the MG nanostructure is attributed to the intrinsic nanoscale structural heterogeneities on the MG surface,which provides a large number of hotspots for the localized electromagnetic field enhancement affirmed by the finite-difference time-domain(FDTD)simulation.Our works show that the MG could be a new potential SERS material with low cost and good durability,well extending the functional application of this kind of material.
基金Project supported by the National Natural Science Foundation of China (Grant No.50872147)the National High Technology Research and Development Program of China (Grant No.2007AA03Z305)the Special Doctoral Foundation of the Ministry of Education of China (Grant No.20775030)
文摘Gold nanorods with aspect ratios of from 1 (particles) to 31.6 were synthesized by the seed-mediated method and packed in a highly ordered structure on a large scale on silicon substrates through capillary force induced self-assembly behaviour during solvent evaporation. The gold nanorod surface exhibits a strong enhancing effect on Raman scattering spectroscopy. The enhancement of Raman scattering for two model molecules (2-naphthalenethiol and rhodamine 6C) is about 5-6 orders of magnitude. By changing the aspect ratio of the Au nanorods, we found that the enhancement factors decreased with the increase of aspect ratios. The observed Raman scattering enhancement is strong and should be ascribed to the surface plasmon coupling between closely packed nanorods, which may result in huge local electromagnetic field enhancements in those confined junctions.
基金Open Fund of the Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications(Jinan University)National Natural Science Foundation of China(NSFC)(11274395,11774135,61205165)
文摘Aggregation of metal nanoparticles plays an important role in surface enhanced Raman scattering(SERS). Here, a strategy of dynamically aggregating/releasing gold nanoparticles is demonstrated using a gold-nanofilm-coated nanofiber, with the assistance of enhanced optical force and plasmonic photothermal effect. Strong SERS signals of rhodamine 6 G are achieved at the hotspots formed in the inter-particle and film-particle nanogaps. The proposed SERS substrate was demonstrated to have a sensitivity of 10-12 M, reliable reproducibility, and good stability.
基金supported by the National Natural Science Foundation of China(No.51871003).
文摘Plasmon coupling is an essential strategy to realize strong local electromagnetic(EM)field which is crucial for high-performance plasmonic devices.In this work,multiple plasmon couplings are demonstrated in three-dimensional(3D)hybrid plasmonic systems composed of polydimethylsiloxane-supported ordered silver nanocone(AgNC)arrays decorated with high-density gold nanoparticles(AuNPs)which are fabricated by a template-assisted physical vapor deposition process.Strong interparticle coupling,particle-film coupling,inter-cone coupling,and particle-cone coupling are revealed by numerical simulations in such composite nanostructures,which produce intense and high-density EM hot spots,boosting highly sensitive and reproducible surface enhanced Raman scattering(SERS)detection with an enhancement factor of-1.74×10^(8).Furthermore,a linear correlation between logarithmic Raman intensity and logarithmic concentration of probe molecules is observed in a large concentration range.These results offer new ideas to develop novel plasmonic devices,and provide alternative strategy to realize flexible and high-performance SERS sensors for trace molecule detection and quantitative analysis.
基金supported by the National Natural Science Foundation of China(No.61275187,No.61378089,and No.31300691).
文摘Contamination by accidental cutaneous contact with the commercial products and the air pol-hutants raised a considerable health and safety issue.This study aimed to trace the dynamics of the 20 nm gold nanopartide(GNP)penetration and accumulation in rat skin tissues using a surface-enhanced Raman scattering(SERS)techmique.After the topical application of GNPs on rat skin surface,the SERS spectra were recorded for every 15 pum to an overall depth of 75 pum from skin surface for 150 min.The processes of GNP penetration in rat skin were accompanied by aggregation of GNPs,which affected SERS spectra.The results revealed that 20 nm GNPs can penetrate through stratum corneum layer,viable epidermis layer,and then into dermis layer.This study demonstrated for the first time the potential of SERS spectroscopy to monitor the penetration and accumulation of GNPs in rat skin.
基金supported by the National Basic Research Program of China(Grant No.2013CB934301)the National Natural Science Foundation of China(Grant No.50931002)+1 种基金the Research Project of Chinese Ministry of Education(Grant No.113007A)the Initiative Scientific Research Program of Tsinghua University,China
文摘An effective surface enhanced Raman scattering(SERS) substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface in order to create numerous "hot spots". The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.
文摘A fabrication process based on the self-assembling polystyrene spheres is proposed to obtain hole arrayed metal-insulator-metal (HA-MIM) structure for surface enhanced Raman scattering (SERS). The localized field enhancement aroused by the gap resonance in the HA-MIM structure is analyzed by finite-different time domain (FDTD) method. With reference to the theory result, the structure is experimentally fabricated and the Raman scattering spectrum of rhodamine 6G (R6G) is measured by a miniaturized Raman spectrometer. The results shows that the enhancement factor is 3.85 times higher than the control sample with single layered metal hole array. The fabrication process to obtain the HA-MIM SERS substrate is reproducible, fast, large area and low cost.
基金Project supported by Hi-Tech Research and Development Program of China(Grant Nos.2007AA05Z436 and 2009AA050602)Science and Technology Foundation of Tianjin(Grant No.08ZCKFGX03500)+3 种基金National Basic Research Program of China(Grant Nos.2006CB202602 and 2006CB202603)National Natural Science Foundation of China(Grant No.60976051)International Cooperation Project between China-Greece Government(Grant Nos.2006DFA62390 and 2009DFA62580)Program for New Century Excellent Talents in University of China(Grant No.NCET-08-0295)
文摘A combined Ag nanoparticle with an insulating or conductive layer structure has been designed tor molecular detection using surface enhanced Raman scattering microscopy. Optical absorption studies revealed localized surface plasmon resonance, which shows regular red shift with increasing environmental dielectric constant. With the combined structure of surface enhanced Raman scattering substrates and rhodamine 6C as a test molecule, the results in this paper show that the absorption has a linear relationship with the local electromagnetic field for insulating substrates, and the electrical property of the substrate has a non-negligible effect on the intensity of the local electromagnetic field and hence the Raman enhancement.
基金supported by the National Basic Research Program of China under Grant No. 2006cb302905the Key Program of National Natural Science Foundation of China under Grant No. 60736037the National Natural Science Foundation of China under Grant No. 10704070
文摘Surface Plasmon Resonance (SPR) is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering (SERS) probe. Long-period fiber gratings are fabricated on single mode polymer optical fiber (POF) with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.
基金Project supported by the National Key Research Program of China(No.2011ZX01015-001)the National Basic Research Program of China(Nos.2011CBA00608,2012CB619203,2015CB351902,2015CB932402)
文摘Coherent anti-Stokes Raman scattering spectroscopy(CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels,while the enhancement factor for surface plasmon resonances(SPR) are extensively used to increase the local field close to the oscillators and which can obtain high enhancement. In this work, we investigate the enhancement factor of our structure for surface-enhanced coherent anti-Stokes Raman scattering. The absorption spectrum of the structure has been studied, a wide range of absorption has been realized. The enhancement can be as high as 10^(16) over standard CARS. Our design is very useful for improving the enhancement factor of surface-enhanced coherent anti-Stokes Raman scattering.
基金We greatly appreciate the support of the National Natural Science Foundation of China(no.21475088)the International Joint Laboratory on Resource Chemistry(IJLRC)+2 种基金the Shanghai Key Laboratory of Rare Earth Functional MaterialsShanghai Engineering Research Center of Green Energy Chemical Engineering(18DZ2254200)the Shanghai Municipal Education Comnfittee Key Laboratory of Molecular Imaging Probes and Sensors.
文摘Creatinine level in urine is an important biomarker for renal function diseases,such as renal failure,glomerulonephritis,and chronic nephritis.The Au@MIL-101(Fe)was prepared by in situ growth of Au nanoparticles in MIL-101(Fe)as a selective SERS substrate.The Au@MIL-101(Fe)offers the great local surface plasmon resonance(SPR)effect due to gold nanoparticles aggre-gation inside metal-organic frameworks.The framework structure could enrich trace target samples and drag them into SPR hot spots.The optimal Au@MIL-101(Fe)composite substrate is used for analyzing creatinine in urine and the limit of detection is down to 0.1μmol/L and a linear relationship is ranging from 1μmol/L to 100μmol/L.
文摘Metal foils for Raman scattering were prepared by HNO_3 etching method. These foils werefound to exhibit a strong SERS effect and excellent thermal stability. SERS spectra of cystaminehave been taken to illustrate the usefulness of this sample preparation method in the studies ofchemisorption. The ring opening reactions of an epoxy compound have been observed on the topof chemisorbed cystamine on silver foils.
基金This work was supported by the National Key Project for Fundamental Research "Macromolecular Condensed State", the State Science and Technology Commission of China and the Science Foundation of Polymer Physics Laboratory, Chinese Academy of Sciences.
文摘Polystyrene films were adsorbed onto a silver surface from dichloromethane solutions with concentrations of 0.1 to 12 wt%, and then studied by the surface enhanced Raman technique. A critical concentration for coil interpenetration was observed.
基金support by the Visiting Scholar Foundation of the Key Lab in Nankai University, and to financial support by the National Natural Science Foundation of China (No. 29974014).
文摘When colloidal silver particles were chemically deposited onto polymer film as an over-coating layer, surface-enhanced Raman scattering (SERS) spectra could be collected for the surface analysis. SERS measurements of liquid crystal film were successfully performed without disturbing the surface morphology.
基金Supported by the National Natural Science Foundation of China(12274379,11904332 and 11904270)。
文摘Significant amplification of surface enhanced Raman scattering(SERS)signals can be achieved mainly by the electric field enhancement in metal core-shell nanostructures,and the enhanced magnetic field is rarely studied.In this study,we prepared multi-gap Au/AgAu core-shell hybrid nanostructures by using gold nanocup as the core.The overgrowth processes to grow one,two,and three layers of AgAu hybrid nanoshells can produce Au/AgAu^(1),Au/AgAu^(2),and Au/AgAu^(3) heteronanostructures.The strong plasmon coupling between the core and shell leads to significant electromagnetic field enhancement.Under the synergistic effect of electromagnetic plasmon resonance and plasmon coupling,Au/AgAu core-shell hybrid nanostructures exhibit excellent SERS signals.We also investigate the effect of the interstitial position of the rhodamine B(RhB)molecule on Raman enhancement in Au/AgAu~3 heteronanostructures.This study can provide new ideas for the synthesis of multi-gap Raman signal amplifiers based on magnetic plasmon coupling.