Shell-Isolated Nanoparticle-Enhanced Raman and Fluorescence Spectroscopies: Synthesis and Applications

Shell-isolated nanoparticles (SHINs) composed of a protective shell and a plasmonic metal core have been extensively used in plasmon-enhanced Raman and fluorescence spectroscopy. Whereby, SHIN-enhanced Raman spectroscopy has effectively overcome the material and morphology limitations for traditional surface-enhanced Raman spectroscopy and demonstrates advanced properties in various fields including surface science, chemical analysis, biological and medical assays, and material science. Meanwhile, the fluorescence of the optical species can be enhanced smartly by SHINs due to the localized surface-plasmon resonance effect of the SHINs, the so called SHIN-enhanced fluorescence. In this review, the synthesis of the SHINs is discussed according to the shell materials. Then, the developments and advancements in application of the SHINs in Raman and fluorescence spectroscopies are comprehensively described. Finally, potential future developments for SHINs and SHIN-enhanced spectroscopy are presented.