Research On Integration Of Afm Processing Sers Substrate And Microfluidic System

Surface enhanced Raman scattering(SERS)can amplify the Raman signal by using the local electric field enhancement provided by resonant metal nanoparticles.With the advantages of noninvasive,strong specificity and high sensitivity,It has been widely used in analytical chemistry,surface science and biological science.At the same time,its integrated application with microfluidic system has unique advantages such as less sample demand,fast response,environment-friendly,portable and so on.Atomic force microscope(AFM)has been widely used in the field of micro nano processing because of its advantages of simple processing,in-situ detection and environmental friendliness.The periodic nanostructures such as grating and lattice can be fabricated on the surface of polymer by AFM probe directly,which is expected to be used in the field of SERS substrate fabrication.Firstly,based on the surface plasmon resonance theory,the electromagnetic simulation of AFM processable periodic nanostructures is carried out by COMSOL finite element method.The influence of substrate size and morphology on the electromagnetic enhancement effect is studied,which provides theoretical guidance for using AFM processing periodic nanostructures as SERS substrates.The effects of coating type,coating thickness and incident wavelength on Raman enhancement were studied,which provided theoretical guidance for the preparation of SERS substrate and the parameter selection of Raman spectroscopy experiment.Secondly,AFM was used to conduct mechanical engraving experiments on PC board,and the influence of engraving direction and vertical load on single V-groove engraving was studied,and the single groove engraving process model was established.Based on the single groove engraving process model,the controllable size periodic nano gratings are fabricated by controlling the feed rate.Periodic nanostructures were fabricated by changing the processing angle in the same region for two or more times.The effects of processing parameters,such as probe direction,sample rotation angle and feed rate,on the structure and size of periodic nanostructures were studied.Finally,the processing of periodic nanostructures with controllable size and morphology was realized.The influence of processing range and the same trace superimposed marking on the processing periodic nanoarray is studied and the processing of periodic nanoarrays required by SERS substrate is realized.Finally,based on the processed periodic nanostructures,the SERS substrates were prepared by transfer printing and coating methods.The effects of transfer printing ratio and coating methods on the SERS substrate morphology were studied;Using R6 G as the characterization,the influence of the morphology and size of SERS substrate on the Raman enhancement effect was investigated,and the uniformity and repeatability of SERS substrate were evaluated;The microfluidic channel was prepared by soft lithography,and the SERS substrate was bonded to the microfluidic channel.The SERS microfluidic system was prepared,and the detection of R6 G,malachite green,4-Mpy and other molecules was realized.The application of the system in protein detection was further explored.