Spatially Correlated Single Molecule Fluorescence Spectroscopy and Atomic Force Microscopy Alan Van Orden, Department of Chemistry, Colorado State University These studies are being carried out to explore the relationship between the catalytic activity of the surface and its nanometer scale structure and topography. To accomplish this research, we are developing advanced experimental techniques that allow precise spatial registry of single molecule fluorescence and AFM images. The fluorescence images allow us to determine the precise position of the catalytic sites with nanometer scale precision, as well as the and the catalytic activity of the site. The corresponding AFM images show us the nanometer scale structure of the surface surrounding the catalytic site. Using this information, we can resolve surface defects or other topographical features and see if such features enhance or suppress the catalytic activity. We have been developing AFM and fluorescence instrumentation that will be applied to this project by examining single fluorescent nanocrystals dispersed on mica substrates. We can identifying the nanometer scale positions of the nanocrystals in both the fluorescence and AFM images by utilizing the excitation laser light that is backscattered off of the oscillating AFM tip. Here we present dispersed nanocystals in which we have identified the single nanocrystal contained within the confocal region with nanometer precision. AFM Confocal Region `