Research On Surface Enhancement Raman Scattering Substrate With Gold Nano-particles And Grooves

Surface enhancement Raman scattering(SERS)has replaced the traditional Raman scattering method owing to its strong signal intensity and high sensitivity.When incident light illuminates the noble metal(gold,silver,copper)patterned with sub-wavelength nanometer structures,the electromagnetic field in the nanogaps will be extremely enhanced,which can even be sufficient for single molecule detection.The nano-particles(NPs)on metal surface system has become attractive due to their high reproducibility and ease of assembly.The interaction between localized gap surface polariton(LGSP)of the gold NPs and propagative surface polarization plasmon(SPP)generated by other NPs and by the groove is studied.By the FEM with the Comsol software,the EF in the NP-substrate is calculated with variable diameters of the NP,and variable distance for the case of double NPs.Then,a groove is used to produce the SPP.The effects of propagative SPP in the groove and the LGSP of gold NPs in the NP-substrate gap is investigated.It is concluded that field distribution of propagative SPPs play an important role in determining the optimal positions of NPs to generate the strongest hot spots.The nano-manipulations with Atomic Force Microscope(AFM)are also studied.The experiment proved that the Raman signal intensity can be enhanced with the groove and gold NPs.