Recent Studies on Metal-Embedded Silica Nanoparticles for Biological Applications

Abstract

Recently, silica nanoparticles (NPs) have attracted considerable attention as biocompatible and stable templates for embedding noble metals. Noble-metal-embedded silica NPs utilize the exceptional optical properties of novel metals while overcoming the limitations of individual novel metal NPs. In addition, the structure of metal-embedded silica NPs decorated with small metal NPs around the silica core results in strong signal enhancement in localized surface plasmon resonance and surface-enhanced Raman scattering. This review summarizes recent studies on metal-embedded silica NPs, focusing on their unique designs and applications. The characteristics of the metal-embedded silica NPs depend on the type and structure of the embedded metals. Based on this progress, metal-embedded silica NPs are currently utilized in various spectroscopic applications, serving as nanozymes, detection and imaging probes, drug carriers, photothermal inducers, and bioactivation molecule screening identifiers. Owing to their versatile roles, metal-embedded silica NPs are expected to be applied in various fields, such as biology and medicine, in the future.

Effects of Raman Labeling Compounds on the Stability and Surface-Enhanced Raman Spectroscopy Performance of Ag Nanoparticle-Embedded Silica Nanoparticles as Tagging Materials

“…It allows the deep penetration of biological tissue with minimal absorption by the generated NIR light. Due to these advantages, it is widely used in hazardous substance detection, bioimaging, and therapeutic applications [ 32 , 33 , 34 ]. Although SiO 2 @Ag NPs offer the opportunity to exploit Ag NPs effectively and controllably, Ag NPs can become structurally unstable due to dissolution or Ostwald ripening during storage in the colloidal phase [ 35 ].…”