Fig. 2

a Schematic representation of a typical SEP fabrication route. b–j TEM images of various SEPs: b individual and c dimer Ag-encoded particles. Reproduced with permission from Catala et al. (2016) and Vilar-Vidal et al. (2016). Copyright 2016, Wiley-VCH, and 2016 Royal Society of Chemistry. d Ag nanostars functionalized with a Raman active molecule. Reproduced with permission from Rodríguez-Lorenzo et al. (2012). Copyright 2012, Springer-Nature. e Au nanorods coated with Ag and codified (reproduced with permission from Chen et al. (2016). f, g Spherical SERS-encoded Au particles coated with silica and NIPAM, respectively. Reproduced with permission from Álvarez-Puebla et al. (2009) and Mir-Simon et al. (2015). Copyright 2009, Wiley-VCH, and 2015, American Chemical Society. h Au nanostars functionalized with a Raman reporter and coated with silica. Reproduced with permission from Gao et al. (2015). Copyright 2016, Wiley-VCH, and 2016, Royal Society of Chemistry. i SERS-encoded Au@Ag nanorods deposited on silica-coated magnetic beads. These composite materials are further coated with an outer silica shell decorated with CdTe quantum dots. Reproduced with permission from Wang et al. (2014b). Copyright 2014, Wiley-VCH. j SERS-encoded silver particles coated, first, with silica and then with mesoporous TiO₂ loaded with a fluorescent dye.