Au-Ag Core-Shell Nanospheres for Surface-Enhanced Raman Scattering Detection of Sudan I and Sudan II in Chili Powder

Figure 8

Plot of PCA score for SERS spectra of chili extracts spiked with Sudan I (0.6–1 mg/kg) and Sudan II (0.4–1 mg/kg), using Au@Ag NPs of about 73 nm as substrate.