Fabrication Of Flexible SERS Substrate And Graphene-shielded SERS Substrate

The technology of SERS is a powerful way of analysis in identifying the matetial construction. With the development of nanotechnology, laser light source, weak signal detection techiniques and computer technology, SERS has been widely applied in the fields of surface science, bioanalysis and materials science. In the research of the mechanism of SERS and the application of it, it is necessary to prepare the SERS enhanced substrate which by far has been the hot spot and difficult point as well. A good enhanced substrate should reflect strong SERS enhancement, high signal reproducibility, and certain stability of the substrate. Focusing on the stability and applicability of the current SERS substrate, this essay starts from preparing the flexible SERS substrate of high-performance, and carries out the inspection of the pesticide residue on applying the prepared substrate.In the second chapter of this essay, the flexible SERS substrate is prepared on applying the self-assembly of the polystyrene microsphere and the physical deposition of the metal. On comparison to the other ways of preparing the substrate, it is more timesaving, and the substrate's construction is more organized. On assessing the enhancement of the substrate and the signal repetitiveness of the substrate, we can find that the substrate is of strong enhancement and high signal repetitiveness.In the third chapter of this essay, on applying the flexible SERS substrate prepared this way, the inspection of the malachite green residue on the fish's surface is carried out. A good linear relationship is found between the Raman signal and the consistency of the malachite green, so as to do quantitative analysis. In addition to this, by applying the substrate into the use of inner SERS sensor of the flow cell and the inspection of the CV solution, it comes out that the substrate reflects rapidly from the CV solution consistency.In the fourth chapter of this essay, we covered the substrate with graphene, preserving the substrate as a layer of inert material, it protects the metal of the substrate from being oxidized or damaged by acid and alkaline liquid so as to strengthen the stability of the substrate. Meanwhile, graphene is of good thermal conductivility which prevents the carbonization of the substrate when getting too much energy under the laser radiation. In addition to this, graphene performs certain functions of adsorption and enrichment of the aromatic molecule and DNA. It helps the inspection of these two materials on covering the graphene.