Frf. Fan et Aj. Bard, AN ELECTROCHEMICAL COULOMB STAIRCASE - DETECTION OF SINGLE ELECTRON-TRANSFER EVENTS AT NANOMETER ELECTRODES, Science, 277(5333), 1997, pp. 1791-1793
The current-potential curve at a 2.8-nanometer-radius electrode immers
ed in a solution containing micromolar concentrations of a redox coupl
e, [(trimethylammonio)methyl] ferrocene (Cp(2)FeTMA(+))/Cp(2)FeTMA(2+)
, shows discrete steps (a coulomb staircase) representing single elect
ron-transfer events. Discrete potential steps are also found in the cu
rrent-time curve as the electrode potential relaxes back to equilibriu
m after a coulostatic potential step.