Spatiotemporal-Resolved Hyperspectral Raman Imaging of Plasmon-Assisted Reactions at Single Hotspots

Raman spectroscopy facilitates the study of reacting molecules on single nanomaterials. In recent years, the temporal resolution of Raman spectral measurement has been remarkably reduced to the millisecond level. However, the classic scan-based imaging mode limits the application in the dynamical study of reactions at multiple nanostructures. In this paper, we propose a spatiotemporal-resolved Raman spectroscopy (STRS) technology to achieve fast (similar to 40 ms) and high spatial resolution (similar to 300 nm) hyperspectral Raman imaging of single nanostructures. With benefits of the outstanding electromagnetic field enhancement factor by surface plasmon resonance (similar to 10(12)) and the snapshot hyperspectral imaging strategy, we demonstrate the observation of stepwise Raman signals from single-particle plasmon-assisted reactions. Results reveal that the reaction kinetics is strongly affected by not only the surface plasmon-polariton generation but also the density of Raman molecules. In consideration of the spatiotemporal resolving capability of STRS, we anticipate that it provides a potential platform for further extending the application of Raman spectroscopy methods in the dynamic study of 1D or 2D nanostructures.

Automated summary

This paper proposes a spatiotemporal-resolved Raman spectroscopy (STRS) technology for fast and high spatial resolution hyperspectral Raman imaging of single nanostructures. By utilizing the outstanding electromagnetic field enhancement factor by surface plasmon resonance and the snapshot hyperspectral imaging strategy, the observation of stepwise Raman signals from single-particle plasmon-assisted reactions is demonstrated. The results reveal the impact of both surface plasmon-polariton generation and Raman molecule density on the reaction kinetics.