Spectral absorption of resorufin at different times after the reaction is initiated; each curve is normalized to its own maximum value. The insets show the raw absorption data, background corrected. In both panels, the mixture contains 280±6 μm AR, 5.5±0.1 nm HRP. Panel (A) includes 82.5±0.7 nm GOx and 50.0±0.9 μm glucose (Reactions 1, 2 and 3 occur); (B) includes 27.1±0.5 μm H2 O2 (only Reactions 2 and 3 occur). The curves within each panel are practically identical at all times, clearly demonstrating that no other optically active product besides resorufin is being generated in the reactions.