Patterned Au@Ag Nanoparticles for Surface-Enhanced Raman Scattering

Herein, a surface-enhanced Raman scattering (SERS) substrate with good sensitivity and reproducibility is fabricated by using a "one-step" process. Patterned Au nanostructures were generated employing copolymer brushes as templates, subsequently undergoing the reduction of AgNO3. Impressively, the entire experimental procedure eschews intricate synthesis steps or the necessity for stabilizer additives. The resultant Ag shell layer evenly encapsulates the Au core, yielding densely packed Ag-coated Au (Au@Ag) nanoparticles. These patterned Au@Ag nanoparticle assemblies exhibited remarkable Raman performance, achieving a minimum concentration of detection of 100 pM and an average enhancement factor of 8.8 x 109 when using 4-mercaptobenzoic acid served as the probe molecule. Experimental outcomes and analyses pertaining to thiram, methylene blue, and rhodamine 6G (R6G) confirm the substrate's pronounced Raman effect and its broad range of potential applications.