Improving The Performance Of Surface-enhanced Raman Scattering Spectroscopy Analysis And Biological Detection By Micro/Nanostructures

Micro/nanostructures have attracted extensive research due to their unique properties,and applied in energy harvesting and storage,disease diagnosis,spectral detection,forensic identification,environmental monitoring,food safety and sensing etc.The unique properties of micro/nanostructures can be controlled by adjusting their morphology and size.Herein,we successfully fabricated silver nanoislands on silica spheres platform,silver nanoparticles/silicon nanocone array and size-matching hierarchical micropillar array by combining a variety of technology of micro/nanofabrication.Improving the performance of surface-enhanced Raman scattering(SERS)spectroscopy and biological detection.This thesis mainly includes the following three parts:Firstly,super-hydrophobic silver nanoislands on silica spheres platform was fabricated as SERS substrate based on the combination of spraying and thermal evaporation.The SERS hot spots are evenly distributed on the surface of the silica spheres,which makes the analytes be enriched into hot spot regions,thus the detection sensitivity and reproducibility are improved.Secondly,silver nanoparticles/silicon nanocone array was fabricated as SERS substrate based on the combination of nanosphere lithography,thermal evaporation,metal-assisted chemical etching and droplet-confined electroless deposition.The silver nanoparticles are uniformly deposited on the top of the silicon nanocone array and form hot spots,the detection sensitivity and reproducibility are improved by enriching trace analytes on the hot spots.Various trace contaminants in real samples,such as,crystal violet in lake water,melamine in liquid milk and methyl parathion in tap water can be detected by this substrate.Thirdly,size-matching hierarchical micropillar array was fabricated based on the combination of optical lithography,metal-assisted chemical etching and duplication.This substrate traps circulating tumor cells in the gaps among the micropillars,resulting in an increased interaction between the cells and the substrate.After the modification of antibody,the capture efficiency of this substrate is much higher than other substrates without size-matching structures.Particularly,this substrate presents excellent cytocompatibility and performance in capturing and isolating rare circulating tumor cells from the whole blood samples of breast cancer patients.