| Abstract: | In this report the voltammetry of water‐soluble ferrocene derivatives is used to characterize the surface of carbon fiber microelectrodes before and after both electrochemical and laser activation procedures. Activation of carbon electrodes is necessary to produce a reproducible surface that will allow fast electron transfer. However, the activation method that is best suited for a given analysis can differ with analyte. In order to directly compare activation methods and characterize the resulting electrode performance, the voltammetry of a set of ferrocenes which have fast and well‐known electrochemistry has been used. As expected, electrochemical activation (0.000 to 2.000 V (vs. SSCE) at 500 V/s for 15 seconds) resulted in a hydrophilic surface with increased surface area. Laser pretreatment (20 Hz pulsed nitrogen laser irradiation for 15 seconds) appeared to remove surface oxides thereby producing a more hydrophobic surface that facilitates the adsorption of neutral analytes. In general, anionic ferrocene derivatives exhibited more quasi‐reversible voltammetry and were not as strongly adsorbed as the neutral analyte, particularly with electrochemically activated probes. In addition, neutral analytes show considerable adsorption, particularly at laser‐activated electrodes, while the cationic analyte shows significant adsorption at only the electrochemically‐pretreated electrodes, indicating surface‐specific interactions. |
