Integration of a recyclable silver substrate for in situ surface-enhanced Raman spectroscopy in digital microfluidics

We report a new chip-integrated recyclable SERS substrate, achieved by photochemical deposition of silver nanoparticles onto titanium dioxide (TiO2) thin film. Facilitated by the photocatalytic activity of titanium dioxide the SERS substrate can be recycled for multiple analysis. This enables quasi-real time detection of various compounds in an automated and reusable DMF-SERS platform.

Facile construction of large-area periodic Ag-Au composite nanostructure and its reliable SERS performance

With the maturity of nano-manufacturing technology, nano-materials with excellent surface-enhanced Raman scattering (SERS) activities have evolved from homogeneous materials to composite ones, but the structural uniformity of composite materials has not been effectively improved. We successfully obtained a series of Ag-Au composite nanostructures with high SERS activity by using a two-step deposition and confined spheroidization process and one-step in-situ substitution method. Anodized alumina templates with uniform size distribution were employed as the initial confined template for spheroidizing Ag film into periodic Ag nanoparticles (Ag NPs). The composite nanostructure was simply obtained after a one-step in-situ galvanic reaction based on the Ag NPs arrays. The results showed that the prepared Ag-Au composite nanostructure could be used as reliable SERS substrates with low relative standard deviation value of ∼6.25% for crystal violet molecules. Compared with previous reports, this one-step route greatly simplifies the process of preparing periodic composite nanomaterials and provides a new idea for constructing multi-component metal nanostructures.

A strong charge-transfer effect in surface-enhanced Raman scattering induced by valence electrons of actinide elements

The 6d electrons of Ac atom involved in excited transitions induce a strong CT-SERS enhancement which can be tuned by changing the conformation of pyridine-Ac@Au₇ complexes.