Surface-enhanced Raman scattering (SERS) is a powerful fingerprint vibrational spectroscopy with a single-molecule detection limit, but its applications are generally restricted to 'free-electron-like' metal substrates such as Au, Ag and Cu nanostructures. We have invented a shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technique, using Au-core silica-shell nanoparticles (Au@SiO(2) NPs), which makes SERS universally applicable to surfaces with any composition and any morphology. This protocol describes how to prepare shell-isolated nanoparticles (SHINs) with different well-controlled core sizes (55 and 120 nm), shapes (nanospheres, nanorods and nanocubes) and shell thicknesses (1-20 nm). It then describes how to apply SHINs to Pt and Au single-crystal surfaces with different facets in an electrochemical environment, on Si wafer surfaces adsorbed with hydrogen, on ZnO nanorods, and on living bacteria and fruit. With this method, SHINs can be prepared for use in ~3 h, and each subsequent procedure for SHINERS measurement requires 1-2 h.

Samples from naked oat were steeped and germinated under controlled conditions in an incubator. Changes of phenolic compounds and antioxidant activity were investigated in oats during steeping and germination. Results revealed that phenolic compounds and antioxidant activity of oats varied with the difference in steeping and germination stages. Compared with raw grains, short-term steeping treatment did not show significant effects (p > 0.05) on phenolic content. Germination can significantly result in the decrease in bound phenolic and the increase in free and total phenolics. Main phenolic acids and avenanthramides were isolated and quantified by HPLC analysis. During steeping, phenolic acids decreased (p < 0.05); avenanthramide N-(3',4'-dihydroxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid first decreased and then increased (p < 0.05), while avenanthramides N-(4'-hydroxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid and N-(4'-hydroxy-3'-methoxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid did not change significantly (p > 0.05). During germination, gallic and caffeic acids first increased (p < 0.05) and then decreased, whereas p-coumaric and ferulic acids and avenanthramides increased (p < 0.05). Nevertheless, avenanthramides did not change significantly (p > 0.05) during the last stage of germination. Oat extracts exhibited increasing high antioxidant activity with the steeping and germination going on, which may explain that antioxidant activity correlated (p < 0.01) significantly with the content of phenolic compounds.