Surface-enhanced Raman scattering (SERS) is a powerful technique that provides fingerprint vibrational information with ultrahigh sensitivity, even down to single molecular level. However, only a few metals (gold, silver and copper) yield a large SERS effect, and they must be rough at the nanoscale. The lack of materials and morphology generality problems had limited the breadth of practical applications of SERS in a variety of fields. Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) was therefore invented to break the long-standing limitation of SERS. In SHINERS, Au/Ag@SiO2 core-shell nanoparticles were rationally designed. The Au/Ag core as plasmonic antenna provides high electromagnetic field to enhance the Raman signals of probed molecules, while the ultra-thin, uniform and pinhole-free silica shell separates the Au/Ag cores from the system under study and ensures no interference from processes involving the SERS-active cores, thus, providing the original information from the target systems. Shell-isolated nanoparticles (SHINs) can be spread as “smart dusts” over surfaces with diverse compositions and morphologies, and it has already been applied to a number of challenging systems eg., from single-crystal electrode surface to semiconductor surface in industry, from living bacteria to pesticide residue detection for food safety.
Nanoparticles? the Universe?