Figure 5.

Diffusion of H₂O₂ in a type II device with an array of 9 × 10 cathodic and anodic poles. From left to right: ECL images captured at 60 and 120 s after dropping 10 μL of 100 mM H₂O₂ solution onto 1 mL of 50 mM PBS (pH 7.4) containing 100 mM KNO₃, and a layout of the array of cathodic poles in the sensing chamber. The orange arrow indicates the location where the H₂O₂ solution was dropped. Applied voltage: 2.4 V.