Investigations of the relationships between structure and electrochemical properties of fullerenol nanoaggregates

Abstract

Hybrid materials containing fullerenols have been used as electrodes in many applications, such as electrochemical biosensors for different targets or in hydrogen and oxygen reduction reactions. However, electrodes modified with fullerenols and without other electroactive materials are not much explored, and the electrochemical behavior of fullerenols themselves is not well-established in the literature. Herein, we report the basic electrochemical characterization of electrode modified with fullerenol and some correlations between material structure and electrochemical behavior. The prepared fullerenol is composed of nanoaggregates dispersed in an organic solvent. Although the electrode modified with pristine fullerene is slightly less active to [Fe(CN)6]3−/4− concerning bare glassy carbon electrode (GCE), the fullerenol-based electrode presents a much lower activity that is slightly increased after electrochemical reduction. The drying process greatly influences the electrochemical performance of the electrodes modified with fullerenol, and fast drying can form ruptures with micrometric dimensions that provide a particular behavior towards the anionic probe. The reduction process increases the number and sizes of these ruptures and changes the electrochemical response. Moreover, the fullerenol-based electrode is more active for [Ru(NH3)6]3+ than the bare GCE, and the activity was increased after reduction. However, the electrochemical response to the cationic probe is characteristic of macroelectrodes regardless of the drying process or reduction. This work opens new perspectives in the electrochemical studies of modified carbon nanomaterials, with the possibility of producing carbon-based electrodes selective to charged probes by controlling the carbon materials' molecular and microscale structures.