Au@Au@Ag double shell nanoparticles were fabricated and characterized using TEM,STEM-mapping and UV-Vis methods.Using crystal violet as Raman probe,the surface-enhanced Raman scattering(SERS)activity of the as-prepare...Au@Au@Ag double shell nanoparticles were fabricated and characterized using TEM,STEM-mapping and UV-Vis methods.Using crystal violet as Raman probe,the surface-enhanced Raman scattering(SERS)activity of the as-prepared Au@Au@Ag nanoparticles was studied by comparing to Au,Au@Ag and Au@Au core-shell nanoparticles which were prepared by the same methods.Moreover,it can be found that the SERS activity was enhanced obviously by introduction of NaCl and the concentrations of NaCl played a key role in SERS detection.With an appropriate concentration of NaCl,the limit of detection as low as 10^(-10)mol/L crystal violet can be achieved.The possible enhanced mechanism was also discussed.Furthermore,with simple sample pretreatment,the detection limit of 5μg/g Rhodamine B(RhB)in chili powders can be achieved.The results highlight the potential utility of Au@Au@Ag for detection of illegal food additives with low concentrations.展开更多
Simultaneous and quantitative detection of multiple exosomal micro RNAs(miRNAs)was successfully performed by a surface-enhanced Raman scattering(SERS)assay consisting of Raman probes and capture probes.In this design,...Simultaneous and quantitative detection of multiple exosomal micro RNAs(miRNAs)was successfully performed by a surface-enhanced Raman scattering(SERS)assay consisting of Raman probes and capture probes.In this design,the asymmetric core-shell structured Au@Au@Ag nanoparticles were first synthesized by layer-by-layer self-assembly method and modified with different Raman molecules and recognition sequences(poly A-DNA)to prepare the surface-enhanced Raman probes.Then,the streptavidinmodified magnetic beads were used to immobilize the biotinylated DNA capture sequences(biotin-DNA)to obtain capture probes.In the presence of target exosomal miRNAs,the Raman probes and capture probes could bind to the target exosomal miRNAs in the partial hybridization manner.Thus,the developed SERS sensor could indicate the target miRNAs levels in the buffer solution.Using breast cancerrelated miRNAs as model targets,the limits of detection of this sensor were determined to be 1.076 fmol/L for synthetic miR-21,0.068 fmol/L for synthetic miR-126,and 4.57 fmol/L for synthetic miR-1246,respectively.Such SERS sensors were further employed to detect the miR-21 in 20%human serum and the extraction solution of exosomes,respectively.Therefore,simultaneous and multiplex detection of cancerrelated exosomal miRNAs by this assay could provide new opportunities for further biomedical applications.展开更多
基金supported by the National Natural Science Foundation of China(No.21505118)the Natural Science Foundation of Jiangsu Province of China(BK 20150438)Postdoctoral Research Funding Program of Jiangsu Province of China(No.1701133C).
文摘Au@Au@Ag double shell nanoparticles were fabricated and characterized using TEM,STEM-mapping and UV-Vis methods.Using crystal violet as Raman probe,the surface-enhanced Raman scattering(SERS)activity of the as-prepared Au@Au@Ag nanoparticles was studied by comparing to Au,Au@Ag and Au@Au core-shell nanoparticles which were prepared by the same methods.Moreover,it can be found that the SERS activity was enhanced obviously by introduction of NaCl and the concentrations of NaCl played a key role in SERS detection.With an appropriate concentration of NaCl,the limit of detection as low as 10^(-10)mol/L crystal violet can be achieved.The possible enhanced mechanism was also discussed.Furthermore,with simple sample pretreatment,the detection limit of 5μg/g Rhodamine B(RhB)in chili powders can be achieved.The results highlight the potential utility of Au@Au@Ag for detection of illegal food additives with low concentrations.
基金the Project of National Natural Science Foundation of China(Nos.21775036,21735002,21874035 and 22174044)。
文摘Simultaneous and quantitative detection of multiple exosomal micro RNAs(miRNAs)was successfully performed by a surface-enhanced Raman scattering(SERS)assay consisting of Raman probes and capture probes.In this design,the asymmetric core-shell structured Au@Au@Ag nanoparticles were first synthesized by layer-by-layer self-assembly method and modified with different Raman molecules and recognition sequences(poly A-DNA)to prepare the surface-enhanced Raman probes.Then,the streptavidinmodified magnetic beads were used to immobilize the biotinylated DNA capture sequences(biotin-DNA)to obtain capture probes.In the presence of target exosomal miRNAs,the Raman probes and capture probes could bind to the target exosomal miRNAs in the partial hybridization manner.Thus,the developed SERS sensor could indicate the target miRNAs levels in the buffer solution.Using breast cancerrelated miRNAs as model targets,the limits of detection of this sensor were determined to be 1.076 fmol/L for synthetic miR-21,0.068 fmol/L for synthetic miR-126,and 4.57 fmol/L for synthetic miR-1246,respectively.Such SERS sensors were further employed to detect the miR-21 in 20%human serum and the extraction solution of exosomes,respectively.Therefore,simultaneous and multiplex detection of cancerrelated exosomal miRNAs by this assay could provide new opportunities for further biomedical applications.
