Research On Preparation And Properties Of Metal/Biological Composite SERS Substrate

As a spectral analysis,surface enhanced Raman scattering(SERS)is widely used in biomedicine,food safety,environmental monitoring and other fields due to its high sensitivity,fast response and non-destructive analysis.Preparation of SERS substrate is an important part in the process of Raman spectroscopic detection,and also the key to successfully realize the enhancement of Raman signal of the molecules to be tested.In recent years,in order to further promote the development of SERS technology,people have made a lot of discussions on the preparation of low cost and high performance SERS substrate.The research on composite SERS substrate has gradually attracted close attention from related fields.In this paper,natural biomaterials(dragonfly wings and cicada wings)were used as templates,and magnetic nickel iron alloy was deposited on the surface of natural materials by magnetron sputtering technology.Different noble metal materials were then modified on them and the solid-state composite SERS substrates were obtained.At the same time,the SERS properties of the substrates were further studied.The research contents are as follows:Firstly,nickel iron alloy and copper were successively sputtered on the surface of threedimensional irregular dragonfly wings by magnetron sputtering technology.By optimizing the sputtering time,the morphology and size of the substrate were changed,and the appropriate nanostructure was found,and the density of “hot spots”on the surface of the substrate was adjusted.SERS substrates with different enhancement effects were obtained.The surface morphology of the substrate was characterized by scanning electron microscope and the optimal substrate was selected by Raman spectrometer and its SERS performance was analyzed.Secondly,cicada wings with three-dimensional regular nanoarrays were selected as templates,and Ni Fe alloy was deposited on the surface of cicada wings.The thickness of the Ni Fe alloy film was controlled by the change of the sputtering time,and the Ni Fe/cicada wing substrate was obtained.Rhodamine 6G was used as the probe molecule to screen the substrate with the best enhancement effect,and the enhancement performance of the substrate was analyzed.Finally,in order to improve the SERS performance of the substrate,silver nanoparticles with an average diameter of about 30 nm were modified on the surface of Ni Fe/cicada wing substrate.The roughness of the substrate surface is changed,so as to the number and the quality of “hot spots”is improved.The adhesion of silver nanoparticles was observed by scanning electron microscope,and the enhancement performance,uniformity and reproducibility of the substrate were studied.And the substrate was applied to the quantitative detection of crystal violet.