Regulation Of Metal Nanostructures Plasmon And Its Application

The plasmon characteristic of metal nanostructures refers to the property that metal nanostructures can be excited collectively by the surface electrons when excited by photons or electrons.Metal nanostructures are widely used in molecular detection and biomedical fields because of their special optical properties such as strong resonance absorption and scattering.At the same time,because the optical properties are dependent on the shape and size of the nanoparticles themselves,it is feasible to change the plasmon characteristics of the nanoparticles by regulating the nanostructures.This thesis focuses on two methods of regulating metal nanostructures.Two types of gold-based nanoparticle structures:nanoflowers and nanodumbbell-shaped particles were prepared by regulation.The morphological evolution path,structural characteristics,and optical characteristics were discussed.The main content and research results of this article are as follows(1)A convenient and reproducible method was used for fabricating large-area gold nanoflower arrays with micro-nano scale multilevel structures.First,the self-assembly process was used to achieve rapid alignment of double-layered silica nanospheres.On this basis,the upper nanospheres were used as a mask to achieve controlled etching of the lower nanosphere array.Then,by controlling the thickness of the sputtered gold layer and combining optimization with simulation,a gold nanoflower array with maximum local electromagnetic field enhancement was obtained.Finally,by using benzoic acid as a marker,nanomolar detection sensitivity could be achieved.This nanoflower has a special three-dimensional structure.In addition to the surface-enhanced Raman spectroscopy-based detection,such resulting nanoflower array has great potential for applications such as nanoparticle filtration and nanomotors(2)Gold nano dumbbell-shaped particles with near-infrared two-region optical absorption were prepared.Using the specific nucleic acid sequence to mediate the secondary growth of the nano-gold rods,dumbbell-shaped gold nanoparticles were obtained,and the absorption peak red shift was achieved.Experiments show that the prepared gold nano dumbbell particles have high photothermal conversion efficiency,and excellent light-to-heat stability and reproducibility.In addition,it has excellent photoacoustic imaging performance.Therefore,gold nano dumbbell particles with controllable plasmon performance can be used as photothermal therapeutic agents and photoacoustic imaging contrast agents,and have promising applications in the field of nanomedicine.