DNA origami have been established as versatile templates to fabricate plasmonic nanostructures in predefined shapes and multiple dimensions. Limited to the size of DNA origami, which are approximate to 100 nm, it is h...DNA origami have been established as versatile templates to fabricate plasmonic nanostructures in predefined shapes and multiple dimensions. Limited to the size of DNA origami, which are approximate to 100 nm, it is hard to assemble more intricate plasmonic nanostructures in large scale. Herein, we used rectangular DNA origami as the template to anchor two 30-nm gold nanoparticles(Au NPs) which induced dimers nanostructures. Transmission electron microscopy(TEM) images showed the assembly of Au NPs with high yields. Using the linkers to organize the DNA origami templates into nanoribbons,chains of Au NPs were obtained, which was validated bythe TEM images. Furthermore, we observed a significant Raman signal enhancement from molecules covalently attached to the Au NP-dimers and Au NP-chains. Our method opens up the prospects of high-ordered plasmonic nanostructures with tailored optical properties.展开更多
Cascaded optical field enhancement(CFE)can be realized in some specially designed multiscale plasmonic nanostructures,in which the generation of extremely strong fields at nanoscale volume is crucial for many applicat...Cascaded optical field enhancement(CFE)can be realized in some specially designed multiscale plasmonic nanostructures,in which the generation of extremely strong fields at nanoscale volume is crucial for many applications,for example,surface-enhanced Raman spectroscopy(SERS).In this paper,we propose a strategy for realizing a high-quality plasmonic nanoparticle-in-cavity(PIC)nanoantenna array,in which strong coupling between a nanoparticle(NP)dark mode with a high-order nanocavity bright mode can produce strong Fano resonance at the target wavelength.The Fano resonance can effectively boost the CFE in a PIC.A cost-effective and reliable nanofabrication method is developed using room temperature nanoimprinting lithography to manufacture high-quality PIC arrays.This technique guarantees the generation of only one gold NP at the bottom of each nanocavity,which is crucial for the generation of the expected CFE.To demonstrate the performance and application of the PIC array,the PIC array is employed as an active SERS substrate for detecting 4-aminothiophenol molecules.An experimental SERS enhancement factor of 2×10^(7) is obtained,which verifies the field enhancement and the potential of this device.展开更多
基金supported by the National Natural Science Foundation of China(No.21475064)the Natural Science Foundation of Jiangsu Province(No.BK20151504)+4 种基金Program for Changjiang Scholars and Innovative Research Team in University(No.IRT_15R37)Sci-Tech Support Plan of Jiangsu Province(No.BE2014719)the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.PAPD,YX03001)the Mega-projects of Science and Technology Research(No.AWS13C007)NUPTSF(No.214175)
文摘DNA origami have been established as versatile templates to fabricate plasmonic nanostructures in predefined shapes and multiple dimensions. Limited to the size of DNA origami, which are approximate to 100 nm, it is hard to assemble more intricate plasmonic nanostructures in large scale. Herein, we used rectangular DNA origami as the template to anchor two 30-nm gold nanoparticles(Au NPs) which induced dimers nanostructures. Transmission electron microscopy(TEM) images showed the assembly of Au NPs with high yields. Using the linkers to organize the DNA origami templates into nanoribbons,chains of Au NPs were obtained, which was validated bythe TEM images. Furthermore, we observed a significant Raman signal enhancement from molecules covalently attached to the Au NP-dimers and Au NP-chains. Our method opens up the prospects of high-ordered plasmonic nanostructures with tailored optical properties.
基金We acknowledge the support by the National Natural Science Foundation of China(Projects No.11474180,and No.61227014)the Ministry of Science and Technology of China(Project No.2011BAK15B03).
文摘Cascaded optical field enhancement(CFE)can be realized in some specially designed multiscale plasmonic nanostructures,in which the generation of extremely strong fields at nanoscale volume is crucial for many applications,for example,surface-enhanced Raman spectroscopy(SERS).In this paper,we propose a strategy for realizing a high-quality plasmonic nanoparticle-in-cavity(PIC)nanoantenna array,in which strong coupling between a nanoparticle(NP)dark mode with a high-order nanocavity bright mode can produce strong Fano resonance at the target wavelength.The Fano resonance can effectively boost the CFE in a PIC.A cost-effective and reliable nanofabrication method is developed using room temperature nanoimprinting lithography to manufacture high-quality PIC arrays.This technique guarantees the generation of only one gold NP at the bottom of each nanocavity,which is crucial for the generation of the expected CFE.To demonstrate the performance and application of the PIC array,the PIC array is employed as an active SERS substrate for detecting 4-aminothiophenol molecules.An experimental SERS enhancement factor of 2×10^(7) is obtained,which verifies the field enhancement and the potential of this device.
