Preparation And Application Of Metal Nanoparticle Substrate For Surface Enhanced Raman Spectroscopy

SERS(Surface-enhanced Raman Scattering, SERS) spectra with its simple, fast detection speed, high accuracy, low loss advantages, has been widely used to determine the molecular structure and description intermolecular interactions and molecular detection of various fields as a powerful analysis tool. With the continuous development of SERS recently increasing the observation and application, SERS spectrum technology plays an increasingly important role in SERS detection sensitivity and new phenomena. However, how to obtain a Raman signal enhancement is obvious, and easy to get a signal reproducible SERS substrate has been bound Raman spectroscopy is a very important area of research, and prepared for the actual test substrate, such as in pesticide residues has done a lot of outstanding contributions, so that pesticide original complex process has been simplified to achieve the purpose of rapid detection, convenient and high accuracy. Let it out of the laboratory into the real world, for the detection and real-life applications of the sample,is the top priority, which is the research will go on a very important impetus. In this paper, sol-gel method is based on the use of sol-gel synthesis of uniform size and structure of nanoparticles and modified, prepared with unique optical properties, gold and silver nano-specific morphology SERS substrate, which has the advantage of enhanced Raman unique characteristics of practical application of research, studies and theoretical calculations performed under test. Specific experiments include:(1) In this paper, by self-assembly with electrochemical chronoamperometry method combined on ITO conductive glass assembled into ordered arrays of gold nanoparticles. And coated on a substrate layer of ordered arrays of gold nanoparticles inert silica shell using spectroscopic ellipsometer of coating process was tested, to ensure the shell pinhole-free premise makes minimum shell thickness, byelectrochemical method to verify the integrity of the shell coated stability margin nano ordered array structure and optical properties. And discussed the prospects of this substrate。(2) The use of ordered arrays of gold nanoparticles synthesized for testing pesticide residues in food, experiment highlights the sensitivity and applicability of this substrate. Experiments have been detected carbaryl limit on this base about 0.05 ppm, with good sensitivity. Raman peak intensity and concentration gradient of the linear correlation coefficient of 0.988, has a good linear relationship. And pesticide measured according to DFT theoretical calculation, the theoretical ideal state Raman spectrum pesticides, and adsorbed on gold nanoparticles Pseudopotentials Raman spectroscopy, and its calculation of the potential distribution of the peaks been assigned。(3) The metal nanoparticle has a unique morphology and optical properties due to the unique catalytic properties which has caused widespread concern. In this paper, the seeds of silver nanoparticles to levodopa as reductant chloroauric acid synthesized gold nanoparticles with unique sea urchin-like morphology. And reducing the amount of seed as well as the amount of silver nano urchin-like particles on the nano-topography influence has been explored, and were characterized by visible spectroscopy, electron microscopy and XRD methods such as by UV. And for the detection of pesticide found its excellent Raman enhancement.