| Due to the excellent surface plasmon resonance（SPR）effect,gold nanoparticles have been widely used in the fields of biosensor,surface enhanced Raman spectroscopy and optical components.Its optical properties are highly dependent on the parameters such as morphology,structure and size,and the performance of optical devices can be controlled by adjusting the material composition and spatial arrangement of the structure,such as light absorption,reflection and Raman signal strength.Due to the unique surface area and high electrical conductivity of graphene and its derivatives,people have begun to study the photoelectric properties of graphene combined with gold nanomaterials（especially gold nanospheres）,and their applications in the field of biosensors.However,the current research mainly focuses on directly mixing gold nanosolutions with graphene solutions to prepare composite structures,while relatively few studies on lamellar graphene and solid gold nanospheres arrays composite.In view of the above problems,a series of structural arrays of gold nanospheres combined with graphene and its derivatives were prepared by polyol synthesis combined with air-liquid interface self-assembly into large-area periodic gold nanosphere arrays,and then combined with wet transfer technology and"spraying+rotation"techniques to obtain a series of structural arrays composed with graphene and its derivatives,and the influence of structural parameters on the optical properties of composite array structures was studied.The specific research work is summarized as follows:（1）The solution of gold nanospheres was obtained by polyol synthesis,in which the size of gold nanospheres can be adjusted by changing the reaction temperature,and the macro-scale gold nanospheres arrays were successfully prepared by gas-liquid interface self-assembly technology.The monolayer graphene film was compounded with gold nanospheres array by wet transfer technology,and the graphene-gold nanospheres array composite structure with good uniformity was obtained.The graphene oxide solution was compounded with the gold nanospheres array by the"spraying+rotation"method to obtain the graphene oxide composite array structure,in which the graphene oxide thickness can be adjusted by changing the spin coating times.The samples were characterized by SEM,the results show that the samples have good periodic arrangement,and they have the advantages of controllable size,long-range order and simple preparation.（2）The optical properties of monolayer and bilayer gold nanospheres arrays with and without graphene films were studied,and the size of gold nanospheres was 77 nm.The results show that compared with the monolayer Au nanospheres arrays,the absorption intensity of the bilayer Au nanospheres arrays can be increased by 15.23%,and the peak is slightly redshifted for 5-6 nm.After compounding with graphene film,the absorption intensity of Au nanospheres arrays in the visible region can be increased by 32.92%,and the maximum redshift of the absorption peak can reach 17nm.This shows that by changing the structure of the Au nanospheres arrays or the composite graphene film,the absorption peak position and peak strength of the Au nanospheres arrays can be controlled and adjusted.This study can provide a new way to regulate the optical properties of nanomaterials.（3）The Raman signal strength and sensitivity of graphene-monolayer and bilayer gold nanospheres arrays structures were studied.The results show that for 77 nm gold nanospheres,when irradiated by 532 nm laser,compared with the Raman intensity of graphene at the same peak,the Raman intensity of monolayer/bilayer gold nanospheres array is 18 and 51 times higher than that of graphene,respectively,and the Raman signal of bilayer gold nanospheres array is 180%higher than that of monolayer array.Compared with the uncomposite arrays,the Raman signal of the graphene-coated monolayer and bilayer gold nanospheres arrays increased by 446%and 892%respectively,and increased by 180 and 280 times compared with the graphene thin film,indicating that the graphene-bilayer gold nanospheres array structure can better enhance the SERS signal.Using graphene-bilayer gold nanospheres array composite structure,the detection limit of R6G molecule can reach 10-6 M.The stability and uniformity of graphene-bilayer gold nanospheres array composite substrate were studied.The relative standard deviation（RSD）of the uniformity result was 1.54%,much less than 15%,and the signal stability was≥20 days.This shows that the substrate has good repeatability and uniformity,and the research results are innovative and will provide a new design idea for the manufacture of efficient and stable surface-enhanced Raman substrates.（4）The optical properties of graphene oxide（GO）-gold nanospheres array structure were studied.The results show that the spin-coating times of GO remain unchanged.When the size of gold nanospheres increases from 55 nm to 190 nm,the light reflection peak position of GO-gold nanospheres array structure is red-shifted by 156 nm,and the peak strength is enhanced by 31.4%.The transmission peak position is red-shifted by 148 nm,and the peak intensity is reduced by 65.7%.When the size of gold nanospheres array remains unchanged（90 nm）,with the increase of GO spraying times,the light reflection peak intensity of GO gold nanoarray structure increases by 31.3%,and the peak position shows a trend of first red shift and then blue shift;at this time,the light transmission peak intensity of the composite structure shows an overall trend of weakening,weakening by 41.7%,and the transmission peak position is red-shifted by 44 nm.This study can provide new ideas for expanding the application of graphene oxide composite Au nanomaterials in optical nanodevices in the future. |
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