Surface characteristics of triethylsilane and phenylsilane hydrogenated structurally small carbon electrodes

Abstract

In this work, we have applied the catalytic reduction of triethylsilane and phenylsilane to hydrogenate conical-tip carbon electrodes (~1.9 μm (standard deviation 0.97 μm; N = 10) tip diameter and ~8.6 μm (standard deviation 0.58 μm; N = 10) axial length) to achieve a H-terminated carbon surface. In addition to forming a hydrophobic sp3-carbon rich surface, these two silane reduction reactions yielded siloxane dendrimers with a bulky side chain and aromatic rings, respectively. In this way, high-molecular weight, amphiphilic molecules present in a biological matrix are deterred from adsorbing on the carbon electrodes, which would otherwise lead to electrode fouling that often compromises electrochemical detection of targeted analytes. This work is focussed on the X-ray photoelectron spectroscopic study and Raman spectroscopic examination of the surface characteristics of the hydrogenated conical-tip carbon electrodes to evaluate the effectiveness of the hydrogenation procedure and to confirm the composition of the electrode surface. The results obtained then aided in validating the type of carbon formed on the hydrogenated carbon electrodes. Additionally, electrochemistry of several redox markers ([Ru(NH3)6]3+, [Fe(CN)6]3− and anthraquinone 2,4-disulfonic acid) were also used to evaluate the surface characteristics of these hydrogenated carbon electrodes.