Mesoporous silica coated core-shell nanoparticles substrate for size-selective SERS detection of chloramphenicol

With the growing popularity of the non-destructive technique, surface-enhanced Raman spectroscopy (SERS) demands a highly sensitive and reproducible plasmonic nanoparticles substrate. In this study, a novel bimetallic core-shell nanoparticles (Au@Ag@mSiO2NP) substrate consisting of a gold core, silver shell, and a mesoporous silica coating was synthesized. The mesoporous coating structure was created by employing template molecules such as surfactant and their subsequent removal allowing selective screening based on the size of analyte mol-ecules. Results showed that the plasmonic substrate could selectively enhance small molecules by preventing large macromolecules to reach the exciting zone of the substrate core, achieving the detection of chloram-phenicol in milk samples with a detection limit of 6.68 x 10-8 M. Moreover, the mesoporous coating provided additional stability to the Au@Ag nanoparticles, leading to the reusability of the substrate. Thus, this work offered a simple and smart Au@Ag@mSiO2NP substrate for effective SERS detection of analytes.

Automated summary

In this study, a novel plasmonic nanoparticles substrate with a mesoporous coating was synthesized for selective enhancement and detection of small molecules. The substrate showed high sensitivity and reproducibility, achieving the detection of chloramphenicol in milk samples. The addition of the mesoporous coating provided additional stability to the nanoparticles, allowing for substrate reusability.