Figure 2.

Strategies for increasing the electromagnetic surface enhanced Raman spectroscopy (SERS) enhancement. (A) (a) Schematic illustration of the capsule; (b,c) Representative TEM micrographs of the capsules; (d) STEM/XED analyses of the capsule composition. Reproduced with permission of [42]. Copyright John Wiley and Sons, 2019. (B) (a) FESEM image of the chestnut-like Au nanocrystal film, (b) local magnified image. Reproduced with permission of [19]. (C) (a–c) SEM images of F-NPs substrate with 100 nm of Ag coating film. Reproduced with permission of [47]. Copyright IOP publishing, 2020. (D) Representative TEM images of (a) the Fe₃O₄@pNIPAM nanohybrid materials containing Ag seeds; (b) the finalFe₃O₄xAgNPs@pNIPAMcomposite microgels. Reproduced with permission of [50]. Copyright American Chemical Society, 2011.