Confocal Laser-induced Deposition Of Surface-enhanced Substrate And Its Raman Spectroscopic Detection Of Furfural

The key to the development of surface-enhanced Raman spectroscopy technology is the preparation of surface-enhanced substrates.The preparation process of traditional surface-enhanced substrates is complicated and difficult to prepare.Existing literature shows that,combined with laser induction technology,the rapid preparation of self-assembled surface-enhanced substrates can be achieved.Therefore,in order to further improve the sensitivity of surface-enhanced Raman spectroscopy for detecting furfural in transformer oil and reduce the difficulty of preparing surface-enhanced substrates,the paper introduces laser induction technology to achieve rapid self-assembly preparation of high-sensitivity surface-enhanced substrates,and combines this technology with micro The combination of fluid control technology improves the uniformity and oxidation resistance of the surface-enhanced substrate,further enhances the reinforcement effect of the substrate,and realizes the reuse of the substrate.The paper simulates and calculates the effects of different substrate materials on the performance of surface-enhanced substrates,and determines the substrate materials for preparing better surface-enhanced substrates;analyzes the influence of laser power and reaction time on substrate preparation;compares and analyzes before and after adding microfluidic technology The difference in the manufacturing method and various properties of the surface-enhanced substrate is determined,and the optimal method of making the surface-enhanced substrate is determined;it is proposed to use microfluidic technology to solve the problem of poor particle uniformity,and to obtain highly uniform surface enhancement through an automated process Substrate;to carry out research on the Raman spectroscopy detection of furfural in transformer oil based on microfluidic deposition of gold film surface-enhanced substrate.The main tasks of the thesis are:（1）Simulation study the influence of different substrates and particle size on the enhancement effect and consistency of the surface-enhanced substrate,and determine the optimal substrate preparation parameters.The gold film is selected as the substrate,and the particle size is in the range of 182±2nm.Under the excitation condition of the incident wavelength of 532 nm,the surface-enhanced substrate has high enhancement performance;the substrate light-induced induction can be changed by adjusting the laser power and reaction time in the deposition state,the increase of laser power and reaction time can speed up the particle growth rate,but too high laser power and too long reaction time will cause the silver nanoparticles to agglomerate and affect the enhancement effect.（2）Study the fabrication methods of self-assembled deposition and microfluidic deposition surface-enhanced substrates,and analyze their microscopic morphology with characterization;the uniformity of particles on the microfluidic deposition substrate is better;the surface-enhanced substrates prepared by the two methods are respectively the same concentration of rhodamine 6G molecular solution was tested,and the enhancement effect and uniformity of the two substrates were compared.The surface enhancement substrate of microfluidic deposition has a better enhancement effect.（3）To study the Raman spectroscopy detection of furfural in transformer oil based on the surface-enhanced substrate of gold film deposited by microfluidics.The mathematical relationship between furfural concentration and characteristic peak area was established,and the characteristic peak of direct Raman spectroscopy was determined to be 1702 cm^-1,and the minimum detection concentration was 2.66 mg/L;the research was based on microfluidic deposition in high-uniform surface-enhanced substrate transformer oil Furfural detection characteristics,confirm the characteristic peak of enhanced Raman spectrum 1667 cm^-1,the shift of the peak position is caused by the adsorption of the surface-enhanced substrate to furfural molecules,which causes the change of the covalent bond vibration mode here;establish the characteristic peak area of Raman and The linear function relationship between furfural concentrations is determined to be 0.14 mg/L,and the calculated enhancement factor can reach 3.95×103;through the analysis of Raman spectra obtained at different positions,it is found that the relative intensity of its characteristic peaks corresponds to The standard deviation value is only 4.76%,which has good uniformity;when measuring furfural in oil with the same substrate at intervals of 5 days within a month,it is found that the Raman signal intensity of the characteristic peak is only attenuated by 19.21%,which has good oxidation resistance;The substrate is cleaned by using the characteristics of microfluid circulation in the channel to realize the reuse of the substrate.