Figure 1

The effect of H ₂ O ₂ concentration on inducing fluorescence in the probes. In the presence of 0.2 μM HRP, 50 mM phosphate pH 7.4 buffer and H₂O₂, oxidation of the probes results in an increase in fluorescence. On the left side of the vertical axis are the fluorescence intensities when no HRP nor H₂O₂ are added to the probe and pH buffer. The fluorometer was calibrated so that pure water resulted in a zero fluorescence and the reaction involving the probe with HRP, pH buffer, and 100 nM H₂O₂ resulted in a fluorescence reading of 1000. The fluorescence intensity results presented in the next two figures are calibrated using two points: the fluorescence intensity of the probe without H₂O₂ or HRP added, and the fluorescence intensity at 1000 nM H₂O₂. The measurements were repeated four times and standard deviation error bars have been added. Many of the error bars, however, are within the size of the points.