FIGURE 1.

Redox activity of AvTsdA adsorbed on a mesoporous nanocrystalline SnO₂ electrode. Electronic absorbance was recorded with the electrode poised at +302 mV (black), +152 to −298 mV at 50-mV intervals (gray), and −648 mV (red). All potentials are quoted versus the standard hydrogen electrode (SHE). The arrows indicate increases in absorbance as the electrode potential was lowered. Inset shows the normalized change in absorbance at 418 nm against the applied potential as the enzyme was reduced (closed squares) and re-oxidized (open squares).