Kuniharu Ijiro
Hokkaido University, Japan
Title: Active gap SERS with plasmonic nanostructures on hydrogels for the sensitive detection of biomacromolecules
Biography
Biography: Kuniharu Ijiro
Abstract
Surface-enhanced Raman scattering (SERS) is a promising approach for the label-free detection of molecules. Th e morphology of metal nanostructures is a primary factor determining the magnitude of signal enhancement on Raman scattering. In general, a narrower gap can form a stronger electromagnetic fi eld, but it makes insertion of analytes into a hot spot more diffi cult. Th is is a trade-off when using conventional SERS substrates. We have fabricated tunable plasmonic nanostructures, the gap distances of which can be controlled by the salt concentration, through the formation of gold nanoparticle self-assembled thin fi lms on solid substrates and their transfer onto poly-acrylic acid gel. Th e extinction spectra shift ed reversibly with volume change of the gel according to the degree of swelling. When the target molecules were injected onto this substrate as the gaps were opened (widened) and SERS was measured aft er the gaps were closed (narrowed), the signals became stronger than that observed without any gap control. Th is method can be served for the sensing of macromolecules such as proteins.