Before each use, the Au electrode was polished with a wet slurry
of 0.05 m Al2O3 on a felt pad.
Then the electrode was successively
ultrasonic rinsed with Piranha (a mixture with 3:7 (v/v) of 30% H2O2
and 98% H2SO4), ethanol, and DDW for 5 min each. The electrode
was then dried under a stream of high purity nitrogen. Finally, 2 L
of 1.5 mg/mL MWNT was placed on a previously conditioned Au
electrode that was held upside-down and was exposed to the air
for 1.0 h at room temperature.