Controlling Ag Nanostructure On Graphene By Block Copolymer Template Method And Researching Their SERS Performance

Surface-enhanced Raman scatting(SERS) as an effective method can be widelyused in the detection of non-polar and symmetric molecules. To extremely lowconcentrations of molecule is mainly used a noble metal such as silver as the reinforcingsubstrate to enhance the Raman signal. Enhance the role of the silver substrate by themultiple effects of silver particle size, shape and internal structure. Block copolymertemplate method has been wildly using in preparing metal materials with controllablemorphology because of its various topography and maneuverability. As a new materialgraphene also has an excellent enhanced performance as a Raman substrate. Based onthe current literature, it was found to have been using graphene and silver nanomaterialscontrolled by block copolymers templates as Raman enhanced substrate respectively,but it has not yet found using block copolymer templates to shape silver nanomaterialson graphene substrate to improve their Raman enhancement properties.In this research silver nano film with different morphology was synthesized byblock copolymer template method on graphene and proved their excellent performanceto enhance Raman signal in detecting crystal violet with enhancement factor (EF)reaches1.12E+08. The relationship between morphology of silver nano materials andperformance of Raman enhanced substrate to crystal violet has also been studied.During removing the block copolymer of the template, oxygen plasma etching methodis more controllable compared with annealing and UV irradiation. And only by oxygenplasma etching method, silver nano material from different template can show differentenhancement factor. Over the different EF based on different morphology of silver nanomaterials, the highest level is as more than10times as that of the lowest one.Meanwhile etching time can also control the morphology of silver nano materials. TEM,AFM and XPS were used to test morphology and ingredient of silver nano film andgraphene basement. Raman spectroscopy was used to test EF of silver and graphenecomposite nanomaterial which was used in Raman scattering of crystal violet.