Figure 3.

Contour plots representations emission versus excitation of LS479 and LS482 in two different aqueous media, acidic (pH = 3) and basic (pH = 8). The intensity of the fluorescence signals are shown in pseudo colors in the online version. Note that the scale for LS479 at pH 3 is four-times higher for better visualization. Excitation was scanned within 560–780 nm range with 2 nm steps; emission was collected from 680 to 880 nm with 1-nm intervals. Rayleigh signals were digitally removed (a stripe 20-nm-wide corresponding to Rayleigh scattering is seen in upper-left corner of each plot).