| Surface-enhanced Raman Scattering(SERS)has been widely concerned and rapidly developed because of its high sensitivity and easy operation.It can be used at the molecular level to get the molecular structure and other information in the biochemical tests,archaeological,art identification,biomedical,food safety and other fields,where it has great potential applications.Therefore,the preparation of surface-enhanced Raman scattering substrate has become a research focus in this field.Now commonly used SERS substrate mostly gold,silver,copper and other precious metals prepared by the metal nano-array,this is because the surface of metal nano-material resonance will lead to a substantial increase in local electric field strength,which played a Raman enhancement,But the metal nanometer array preparation process is quite complex,and its cost is expensive,which makes the application of this SERS substrate has been a certain limit.In recent years,a semiconducting material titanium dioxide SERS substrate,which has no surface plasmon resonance,is gradually emerging.Titanium dioxide can replace the surface plasmon resonance with its own electron transfer properties,and the high refractive index of titanium dioxide can make the laser in the titanium dioxide ordered nano-structure to form a more multiple scattering,increase the probability of contact with the molecules to be tested to enhance the Raman scattering.Therefore,the purpose of this paper is to prepare a three-dimensional ordered nano-structure by simple and economical method and used it as SERS substrate.Detail work contents are as follows:(1)The use of template method in the capillary prepared in the titanium dioxide anti-opal ordered micro-nano structure,by filling the small particle size of titanium dioxide nanoparticles into the polystyrene template gap in the capillary assembly of several different structural color(reflection peak:430 nm,551 nm,667 nm)integrity,Uniform,high quality substrate.(2)The ordered microstructure capillary of titanium dioxide/silica core-shell structure was prepared by atomic layer deposition method.At first we prepare the silica opal-structured ordered microstructure capillary,a complete,uniform and high quality titanium dioxide thin film was deposited on the surface of the silica cylindrical ordered microstructure capillary by atomic layer deposition method.The change of the reflection peak and the change of the surface morphology of the samples with different thicknesses were carried out,with the increase of the coating thickness,the gap of the ordered micro-nano-structure surface is gradually filled,the reflection peak is red-shifted,and the value of the reflection peak grows linearly.(3)In order to systematically study the Raman enhancement effect of titanium dioxide ordered micro-nanostructured substrates,we use the template method and the atomic method to study the properties of the SERS substrate.The two methods were used to prepare different replicas of butterfly wing structure of titanium dioxide,and their respective Raman enhancement effects were compared with two kinds of artificial titanium dioxide ordered micro-nanostructures based on artificial template.Experiments show that these bases have Raman enhancement effect.The titer of titanium dioxide is the highest,the titania/silica shell-core structure is the second,followed by the titanium dioxide butterfly wing structure prepared by atomic layer deposition method.Finally,the titanium dioxide butterfly wing structure prepared by template method,Structure is lower than the former.Compared with the planar base of the butterfly wing structure,the SERS sensitivity of the inner capillary of the capillary is easy to use and shows a better application prospect. |
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