Wide-Field Raman Microscopy with STORM Post-Processing—A Powerful Approach to Increase Spatial Resolution and Acquisition Speed in Raman Imaging

Here, we report on the development of a wide field Raman microscope which significantly improves the speed of acquisition at selected spectral range with spatial resolution in the range of ~200 nm over large field of view. This is achieved by post processing the acquired Raman images with a stochastic optical reconstruction microscopy (STORM)¹ protocol. In STORM the specific blinking of fluorophores is used for their spatial localization. Here, the local intensity fluctuations of the Raman signal enables the localization of the molecules which is utilized to improve the spatial resolution. Several different approaches were presented in the past decades such as tip-enhanced Raman² or confocal Raman spectroscopy³ with the same goal to further increase the spatial resolution of vibrational spectroscopy measurments. However, these point-scanning techniques often require long acquisition times thus limiting the size of the scanned area. In the wide-field STORM-Raman approach this limitation can be overcome by acquiring Raman images at specific spectral ranges over a large time-series which is faster. We demonstrate the potential of this approach on distinct samples such of patterned Silicon, polystyrene microspheres on Silicon wafer and graphene on Silicon/Silicon dioxide substrate. [1] S. Wolter, A. Löschberger, T. Holm, et al., <i>Nat. Methods</i>, <b>2012</b>, 9(11), 1040-1041, [2] U. Kajendirarajah, M. O. Aviles, F. Lagugné-Labarthet, <i>Phys. Chem. Chem. Phys.</i>, <b>2020</b>, 22, 17857-17866, [3] P. J. Pauzauskie, D. Talaga, K. Seo, P. Yang, F. Lagugné-Labarthet, <i>J. Am. Chem. Soc.</i>, <b>2005</b>, 127 (49), 17146-17147