Ultrasensitive SERS Detection Research Articles

Fabrication of Gyroid‐Structured Metal/Semiconductor Nanoscaffolds with Ultrasensitive SERS Detection via Block Copolymer Templating

AbstractSurface‐enhanced Raman scattering (SERS) is a label‐free and powerful technique for monitoring dynamic molecular processes with high sensitivity and reproducibility. SERS has diverse applications in medicine, molecular science, biology, and chemical sensing. In this study, a template‐based approach to create an ultrasensitive SERS‐active substrate is proposed which involves combining nanostructured semiconductors and noble metals. A nanoporous polymer obtained from hydrolyzed gyroid‐forming polystyrene‐block‐poly(l‐lactide) (i.e., PS‐b‐PLLA) is used as a template for Ag reduction and TiO2 sol–gel reaction. After calcination to remove the polymeric template, TiO2 nanoscaffolds appear as self‐supporting 3D nanoobjects with homogeneously and closely distributed Ag nanoparticles, providing a high density of regions with intense local field enhancement (hotspots). Rhodamine 6G molecules are used as probe molecules to demonstrate the SERS performance, revealing a markedly high average enhancement factor of up to 1014. The intrinsic photocatalytic properties of TiO2 can degrade target organic chemicals for the self‐cleaning and reproduction of SERS‐active substrates. Moreover, a simple hydrazine reduction‐based approach is applied for the formation of regenerated Ag/TiO2 nanoscaffolds to reduce the use of Ag‐based SERS‐active substrates, decreasing the costs associated with relevant industrial processes.

Monodispersed Silver-Gold Nanorods Controllable Etching for Ultrasensitive SERS Detection of Hydrogen Peroxide-Involved Metabolites

Monodispersed Silver-Gold Nanorods Controllable Etching for Ultrasensitive SERS Detection of Hydrogen Peroxide-Involved Metabolites

Gyroid-structured Au–Ag periodic bimetal materials for ultrasensitive SERS detection

A gyroid-structured Au–Ag bimetal plasmonic material GSPMMs@Au demonstrates ultrasensitive SERS detection performance due to plasmonic coupling between the Au–Ag interface and gyroid structure with high-density hotspots.

Ultra-sensitive SERS detection, rapid selective adsorption and degradation of cationic dyes on multifunctional magnetic metal-organic framework-based composite

In-situ and real-time ultra-sensitive monitoring for the degradation process of environmental pollutants is always an important issue of concern to many people. Herein, a multifunctional magnetic metal-organic framework (MOF)-based composite has been successfully constructed and applied in monitoring the disposal of cationic dyes. Owing to its particular MOFs shell and internal gold particles, the composite can be used as an efficient SERS substrate to ultra-sensitively detect the cationic dyes. Furthermore, the prepared MOF-based composite is also a peroxidase-like nanozyme, which can catalytically degrade the adsorbed cationic dyes. Additionally, the magnetic core in the MOF-based composite offers a good magnetic separation capacity, which makes a facile and rapid separation of the catalyst from the reacted solution for recyclability. This work has provided a new way to monitor the catalytic degradation process by SERS technique in the co-existence of catalyst and dye molecules in the reaction system, which can effectively eliminate the absorption of the catalyst compared with the UV–vis technique, showing promising applications in in-situ and real-time pollution disposal monitoring.