Surface-enhanced Raman scattering(SERS)provides a novel method for low concentration molecular detection.The performances were highly dependent on the sizes,geometries and distributions of metal nanostructures.Here,hi...Surface-enhanced Raman scattering(SERS)provides a novel method for low concentration molecular detection.The performances were highly dependent on the sizes,geometries and distributions of metal nanostructures.Here,highly sensitive SERS fber probe based on silver nanocubes(Ag NCs)was fabricated,by assembled nanostructures on planar and tapered fber tips.Ag NCs were synthesized by polyol method,and controlled by reductant content,reaction temperatures and crystal growth durations.Tapered fbers with diferent cone angles were prepared by chemical etching.The electromagnetic distribution simulation indicated that nanocubes had stronger electric feld between two cubes and vertex corners than nanosphere,under 532 nm laser excitation.The intensity could reach 53.52 V/m,for cubes with 70 nm edge length.The SERS performance of probes was characterized using crystal violet analyte.The detectable lowest concentration could reach 10^(-9) and 10^(-10) M for planar and tapered fber probes,respectively.The corresponding enhancement factor could be 9.02×10^(7) and 6.22×10^(8).The relationship between SERS peak intensities and analyte concentrations showed well linear,which indicated both fber probes could be applied for both qualitative and quantitative analysis.Furthermore,optimal cone angle of tapered fber SERS probe was 8.3°.The tapered fber SERS probes have highly sensitive activity and great potential in substance detection.展开更多
Surface-enhanced Raman scattering(SERS)is a powerful spectroscopic tool in quantitative analysis of molecules,where the substrate plays a critical role in determining the detection performance.Herein,a silver nanocube...Surface-enhanced Raman scattering(SERS)is a powerful spectroscopic tool in quantitative analysis of molecules,where the substrate plays a critical role in determining the detection performance.Herein,a silver nanocubes/polyelectrolyte/gold film sandwich structure was prepared as a reproducible,highperformance SERS substrate by the wate r/oil inte rfacial assembly method.In addition to the hot spots on the nanocubes surface,the edge-to-edge interspace of the Ag nanocubes led to marked enhancement of the SERS intensity,with a limit of detection of 10~(11)mol/L and limit of quantitation of 10~(10)mol/L for crystal violet.When rhodamine 6 G and crystal violet were co-adsorbed on the Ag nanocube surfaces,the characteristic SERS peaks of the two molecules remained well resolved and separated,and the peak intensities varied with the respective concentration,which could be exploited for concurrent detection of dual molecules.Results from this work indicate that organized ensembles of Ag nanocubes can serve as effective SERS substrate can for sensitive analysis for complex molecular systems.展开更多
基金This research was financially supported by the opening funding of the state key laboratory of silicate materials for architecture(SYSJJ2018-06)the Fundamental Research Funds for the Central Universities(WUT:2016IVA096),China.
文摘Surface-enhanced Raman scattering(SERS)provides a novel method for low concentration molecular detection.The performances were highly dependent on the sizes,geometries and distributions of metal nanostructures.Here,highly sensitive SERS fber probe based on silver nanocubes(Ag NCs)was fabricated,by assembled nanostructures on planar and tapered fber tips.Ag NCs were synthesized by polyol method,and controlled by reductant content,reaction temperatures and crystal growth durations.Tapered fbers with diferent cone angles were prepared by chemical etching.The electromagnetic distribution simulation indicated that nanocubes had stronger electric feld between two cubes and vertex corners than nanosphere,under 532 nm laser excitation.The intensity could reach 53.52 V/m,for cubes with 70 nm edge length.The SERS performance of probes was characterized using crystal violet analyte.The detectable lowest concentration could reach 10^(-9) and 10^(-10) M for planar and tapered fber probes,respectively.The corresponding enhancement factor could be 9.02×10^(7) and 6.22×10^(8).The relationship between SERS peak intensities and analyte concentrations showed well linear,which indicated both fber probes could be applied for both qualitative and quantitative analysis.Furthermore,optimal cone angle of tapered fber SERS probe was 8.3°.The tapered fber SERS probes have highly sensitive activity and great potential in substance detection.
基金supported by the Natural Science Foundation of China(NSFC,Nos.21471103,51631001,11574173 and 21603014)the Scientific Research Base Development Program and the science and technology innovation service ability construction project of the Beijing Municipal Commission of Education。
文摘Surface-enhanced Raman scattering(SERS)is a powerful spectroscopic tool in quantitative analysis of molecules,where the substrate plays a critical role in determining the detection performance.Herein,a silver nanocubes/polyelectrolyte/gold film sandwich structure was prepared as a reproducible,highperformance SERS substrate by the wate r/oil inte rfacial assembly method.In addition to the hot spots on the nanocubes surface,the edge-to-edge interspace of the Ag nanocubes led to marked enhancement of the SERS intensity,with a limit of detection of 10~(11)mol/L and limit of quantitation of 10~(10)mol/L for crystal violet.When rhodamine 6 G and crystal violet were co-adsorbed on the Ag nanocube surfaces,the characteristic SERS peaks of the two molecules remained well resolved and separated,and the peak intensities varied with the respective concentration,which could be exploited for concurrent detection of dual molecules.Results from this work indicate that organized ensembles of Ag nanocubes can serve as effective SERS substrate can for sensitive analysis for complex molecular systems.
