Highly Sensitive Surface-Enhanced Raman spectroscopy for the Surface Corrosion Analysis of Bronze Relics Using the Polyacrylonitrile/Polyvinylpyrrolidone Silver Nanoparticle Flexible Substrate

Surface-enhanced Raman spectroscopy (SERS) is widely used in biological and chemical analyses and in other fields because of its advantages such as high sensitivity and nondestructive nature. Ancient bronze cultural relics of China are exquisitely shaped and highly ornamental. Harmful rust components on the surface of bronze cultural relics have been extensively analyzed. SERS is beneficial to the surface composition analysis of ancient Chinese bronze relics and can be used for accurate characterization with almost zero damage to the surface. In this study, we designed a solution with polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) macromolecules as precursors, which were electrospun and used as the nanofiber substrate. After tannic acid modification, the substrate was loaded with silver nanoparticles by using Tollens' reagent as the silver source and glutaraldehyde as the reducing agent in a water bath. The morphology and size of silver nanoparticles were adjusted by changing the reaction times. The effects of tannic acid and PVP as stabilizers were investigated. R6G and basic copper chloride were used as probe molecules for substrate SERS, and the Raman enhancement factor was calculated. The SERS performance of the substrate with high sensitivity was verified through characterization.