Looking inside solid supports: Confocal Raman Microscopy of polymer beads

摘要

We have used scanning confocal Raman spectroscopy to explore the distribution of reaction sites and reacted sites within a variety of functionalised polymer beads used as solid phase supports for combinatorial chemistry. The balance between reagent diffusion in to the bead material and the rate of the reaction with the polymer support produces different distributions of reacted material within the bead that depend on the nature of the bead material (polystyrene, TentaGel, porous glass) and solvents employed. Comparisons between the use and Raman and fluorescence mapping will be highlighted and the factors that limit the spatial resolution within the bead will be discussed as well as the optical issues that can lead to distortion of the maps. Applications of Raman mapping, at the other end of the discovery process, looking at the distributions of materials in pharmaceutical preparations will be covered and the possible role of polarisation information will be explored.