Fabrication of a new generator-collector electrochemical micro-device: Characterization and applications

The fabrication of a new electrochemical cell where a thin layer of solution (6 nL) is confined between two closely-spaced parallel gold electrodes is described. By polarizing both electrodes at suitable potentials, the forced redox cycling ensures that steady-state conditions are attained almost instantaneously. Voltammetry with ferricyanide solutions demonstrated that the twin-electrode thin-layer cell (TETLC) may operate as a generator-collector device with collection efficiency values of 100%. Experimental results for voltarnmetry and chronoamperometry experiments agreed with predictions based on digital simulation. The increased sensitivity based on the forced redox cycling envisages future applications of the device, as the use of the TETLC as a pre-reactor at quiescent solutions for the determination of paracetamol in Solutions containing ascorbic acid. (c) 2005 Elsevier B.V. All rights reserved.