A series of dual-cylinder microelectrodes with different interelectrod
e gap were constructed with 7 mu m diameter carbon fibers. The collect
ion-efficiency, feedback and shielding properties were studied in deta
il with cyclic voltammetry and chronoamperometry for the case of the f
errocyanide(III/II) couple. The effect of the collector potential on t
he collection-efficiency and the currents at the anode and cathode ele
ctrode were discussed. The application of these dual-cylinder microele
ctrodes to determine the electrochemical reaction mechanism was demons
trated.