Microlithographic procedures are employed to fabricate electrochemical microcells with three coplanar gold-film electrodes (working, auxiliary, and reference) resting on a silicon wafer. The working electrode can be a 11 X 516 or 11 X 256 μm microband or a 11 X 11 μm microsquare, and the cell solution can be a droplet of an aqueous electrolyte solution or a film of an lonically conducting polymer such as lithium triflate dissolved in poly(ethylene oxide). The cyclic voltammetry and chronoamperometry of electroactive species dissolved In these cell media are reported, and the chronoamperometric data are compared to theoretical current-time curves calculated for band microelectrodes. Cyclic voltammetry in an aqueous droplet on the microsquare gives pseudo-steady-state waves, the limiting currents of which quantitatively agree with those for microdisk electrodes of equivalent area. The microllthographically defined microcells can be produced in quantity and can be considered disposable electroanalytical devices, which can be advantageous for routine electroanalytical applications Involving electrode-poisoning reaction systems.
ASJC Scopus subject areas
- Analytical Chemistry