Application of Cu-Graphene (porous)-AgNPs for quantitative SERS detection of transformer Oil-Paper insulation aging characteristics

Surface-enhanced Raman scattering (SERS), functioning as a highly sensitive trace detection tool, has gained popularity as an analytical technique and is extensively employed in diverse domains such as electrical engineering. In this paper, the exploration is conducted regarding the application of surface-enhancement technology in the quantitative detection of the aging characteristics of transformer oil-paper insulation. Flower-like silver nanoparticles (AgNPs) were deposited in situ on a copper foil coated with porous graphene, thereby fabricating a Cu-graphene (porous)-AgNPs surface-enhanced substrate. This substrate effectively prevented the oxidation of nanoparticles while maintaining the SERS activity. By creating apertures in graphene, the adsorption capability of the substrate for organic small molecules like furfural was enhanced, and the size of silver nanoparticles was optimized to achieve better detection outcomes. The performance of the substrate was evaluated using R6G as the probe molecule, and the findings indicated that the substrate exhibited excellent sensitivity, uniformity (RSD values are below 10 %), and antioxidant properties (after 30 days, the peak strength decreased by 8.23 %). When this substrate was utilized for the detection of transformer aging characteristics, the detection limits for furfural, acetone, and methanol reached 0.04 mg/L, 0.18 mg/L, and 0.18 mg/L respectively, fulfilling the analytical requirements of oil-immersed transformers. This research holds significant importance in guaranteeing the stable operation of the power supply system and the smooth development of the national economy.