Channel electrode Chronoamperometry

Compton RG, Coles BA, Fisher AC (1994) Chronoamperometry at channel electrodes. Theory of double electrodes. J Phys Chem 98 2441-2445... 

Fisher AC, Compton RG (1991) Chronoamperometry at channel electrodes a general computational approach. J Phys Chem 95 7538-7542... 

If the reaction proceeds via steps (a), (b), and (c), then we have an ECE process. The sequence (a), (b), (d) corresponds to a DISP reaction. Within the latter scheme there are two further possibilities, depending on whether step (b) or (d) is rate determining. In the former case, we have a DISPl process, since it is a (pseudo-) first-order reaction (in buffer), while in the latter case, we have a DISP2 process, since it is second-order. Conventional electrochemical methods readily recognize DISP2 processes but, with only a few exceptions (double potential-step chronoamperometry and possibly microelectrodes ), they cannot be used to discriminate between ECE and DISPl. It emerges that a combination of ESR transient and electrochemical data from the channel electrode cell can make this distinction. 

Conducting carbon polymer ink, which filled a UV-ablated microchannel, was used to construct the integrated microelectrode on a plastic chip. Both chronoamperometry and CV were employed to detect a model compound (fer-rocenecarboxylic acid) down to 3 iM, corresponding to 0.4 fmol within a volume 120 pL [758], In another report, a carbon-paste electrode was constructed by filling a laser-ablated (PET or PC) channel with C ink. The whole structure was then cured at 70°C for 2 h [189]. 

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