Super-resolution SERS spectral imaging

Increasingly techniques are emerging to detect and characterize molecules on molecular dimensions. The interaction between plasmonic nanostructures and molecules, Surface enhanced Raman scattering (SERS), has demonstrated the ability to enhance Raman signals at low concentrations and even single molecules. The ability to detect the Raman signal from molecules on the nanostructures has enabled high resolution imaging experiments. It has been shown that localization algorithms, common for super-resolution fluorescence imaging, can be applied to SERS signals to enable super-resolution SERS imaging. These initial super-resolution SERS imaging experiments we not able to record the spectral response with the same spatial resolution, either requiring a follow-up measurement or recording the spectrum from the diffraction limited area. The ability to measure the Raman spectrum with same spatial resolution as the image opens new possibilities to understand chemical properties on the nanometer length scale in a variety of applications. We have developed technology to enable super-resolution spectral SERS imaging of plasmonic nanoparticles, where the fluctuations in the surface enhanced Raman scattering (SERS) signal can be analyzed with localization microscopy techniques to provide nanometer spatial resolution of the emitting molecules location and the spectrum associated with each signal can be recorded simultaneously. This approach offers the ability to detect signals buried within samples. This spectrally resolved SERS imaging provides three spatial dimensions, a frequency dimension, and a time dimension, providing increased information characterization of molecules interacting with plasmonic nanoparticles. In this presentation we will discuss the instrumentation, nanoparticles, and data illustrating the imaging of the Raman signal from nanoparticle probes to understand activity in diverse applications.