Figure 3

Intensity distributions of Atto655-Streptavidin single molecules. Comparison of the single molecule Atto655-streptavidin signal on glass and on 1 × 10⁵-2 × 10⁵ nm² nanodots. a) Image of sparsely and randomly distributed Atto655-labeled streptavidin on a substrate without acrylic patches passivated by lipids at 647 nm excitation (unwashed). b) Fluorescence after incubation of the TPP nanodots with Atto655-labeled streptavidin, after washing (647 nm excitation). Over 80% of all dots carry at least one streptavidin. c) Statistical distribution of fluorescence intensity counts per fluorescent spot during 10 ms illumination time, obtained from: (red) sparsely and randomly distributed streptavidin as shown in a) and (blue) from nanodots loaded with streptavidin (see b).