Ultra-High-Speed Dynamics in Surface-Enhanced Raman Scattering
In this perspective, we discuss recent observations related to the temporal dynamics of intensities in surface-enhanced Raman scattering (SERS) experiments. SERS is a well-established and highly active research field, driven by the potential of the technique in analytical and bioanalytical applications. However, there are several fundamental aspects of the effect that still challenge and fascinate researchers in the area. Here we will focus on the recent observation that strong SERS intensity fluctuations (SIFs) are seen when experiments are performed at fast acquisition rates, even when the metal surface is completely covered by an adsorbate. Interestingly, the SIF dynamics indicate bursts of SERS activities that last only a few hundreds of microseconds, followed by a longer period of inactivity. This type of behavior has been observed from several systems and configurations, including single metallic nanoshells and nanostars, immobilized colloidal aggregates, nanoparticle-on-a-mirror configurations, and metal-coated microspheres. This diversity suggests that the dynamical behavior is a fundamental characteristic of the SERS effect. Time-dependent atomic rearrangements within the confined environment of the SERS hotspots are suggested as the main mechanism driving these fluctuations. The dynamical SERS behavior, revealed with high-speed acquisitions, should provide a new direction for the study of atomic reconstruction and single molecule interactions with metallic nanoenvironments with an unprecedented level of detail.
Physics and Engineering
Journal of Physical Chemistry C
Lindquist, Nathan C. and Brolo, Alexandre G., "Ultra-High-Speed Dynamics in Surface-Enhanced Raman Scattering" (2021). Physics and Engineering Faculty Publications. 3.