(A) SESORS experiments were conducted on an in-house-built SORS
system with a point-based collection geometry, i.e., with individual
excitation (E) and collection (C) probes, developed by Asiala et al.
based on the design of Shand and co-workers.21,23 (B) Templates for SESORS experiments were prepared by mixing the
silica powder with silica-coated SERS-active NPs. The NP powders were
then added to a section of the porcine tissue and then covered with
further tissue sections. (C) Hypothetical SESORS imaging regime illustrated
using a square grid, where each vertex on the grid represents a pixel
where the tissue surface is excited by the laser. In the regime illustrated,
the grid represents a 36-pixel (6 × 6) image. (D) Truncated,
baselined, and normalized SERS spectra of PPY (red) and BPE (blue)
powder-based imaging templates developed for this study. Spectra were
collected for 0.1 s using a 785 nm, 400 mW laser.