| As a highly sensitive molecular detection technology,Surface-enhanced Raman scattering（SERS）has been used in many occasions.Synthesizing green,simple and low-cost SERS substrate is one of the goals that researchers have been pursuing.Oxide semiconductor materials have the advantages of easy access to raw materials and rich surface morphology,but the Raman activity of semiconductor materials is too low.To solve this problem,we adopted the method of precious metal modification of semiconductor materials to improve the SERS activity of substrate,prepared several excellent composite substrates,and studied their properties.1.CuO nanowire/Ag composite substrate was prepared by thermal oxidation and magnetron sputtering,and the effects of oxidation temperature,oxidation time and silver film thickness on the SERS characteristics of the composite substrate were studied.The results showed that when the oxidation temperature was 480℃,the oxidation time was 210min,and the silver film thickness was 160nm,the substrate had the best SERS effect.The lowest detection concentration of the CuO/Ag composite substrate for methylene blue is 10-9M,and the analysis enhancement factor is about 2.47×107,which has a certain linear detection ability in the concentration range of10-2M-10-7M.The relative standard deviation（RSD）of Raman strength at 30 different test points on the same substrate is 12.038%,which indicates that the substrate has good uniformity.2.Cuprous oxide thin film was electrodeposited on conductive glass,which was used as sacrificial template for in situ reduction of silver nitrate solution to prepare cuprous oxide/silver composite substrate,and its SERS characteristics were studied.The results showed that the best reinforcement effect was obtained by reacting in 0.3M AgNO3 solution for 7min.The lowest detection concentration of methylene blue on the substrate was 10-10M,and the analysis enhancement factor was about 1.36×108.The relative standard deviation（RSD）of Raman strength at 10 different test points on the same substrate is 10.889%,which indicates that the substrate has good uniformity.At the same time,the test result of the composite substrate after20 days was only 28.75%lower than that of the first day,indicating that the substrate has good stability.3.The bowl cuprous oxide periodic structure was prepared by electrochemical deposition using ordered colloidal crystals of monodisperse polystyrene microspheres as templates.Then,silver was sputtered on cuprous oxide bowl by magnetron sputtering method to construct cuprous oxide/silver composite substrate,and its SERS characteristics were studied.The results showed that the bowl cupreous oxide/silver composite substrate had the best enhanced effect when the silver plating thickness was 40nm,the minimum detection concentration of methylene blue was10-9M,the analysis enhancement factor was about 1.18×107,and the linear detection could be approximately realized within the concentration range of 10-2M to 10-7M.The relative standard deviation（RSD）of Raman strength at 30 different test points on the same substrate is 4.76%,which indicates that the substrate has excellent uniformity. |
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