Patterned Au@Ag Nanoparticles\nfor Surface-Enhanced\nRaman Scattering

Abstract

Herein, a surface-enhanced Raman scattering (SERS) substrate\nwith\ngood sensitivity and reproducibility is fabricated by using a “one-step”\nprocess. Patterned Au nanostructures were generated employing copolymer\nbrushes as templates, subsequently undergoing the reduction of AgNO₃. Impressively, the entire experimental procedure eschews\nintricate synthesis steps or the necessity for stabilizer additives.\nThe resultant Ag shell layer evenly encapsulates the Au core, yielding\ndensely packed Ag-coated Au (Au@Ag) nanoparticles. These patterned\nAu@Ag nanoparticle assemblies exhibited remarkable Raman performance,\nachieving a minimum concentration of detection of 100 pM and an average\nenhancement factor of 8.8 × 10⁹ when using 4-mercaptobenzoic\nacid served as the probe molecule. Experimental outcomes and analyses\npertaining to thiram, methylene blue, and rhodamine 6G (R6G) confirm\nthe substrate’s pronounced Raman effect and its broad range\nof potential applications.