Fabrication of an electrochemical sensing platform based on hydrophilic carbon/gold nanoparticles composite

A simple, economical, and environmentally friendly strategy for the one-pot preparation of a nanocomposite made up of gold nanoparticles and Electrogenerated Hydrophilic Carbon material (EHC), is reported in this work. The EHC material works itself as the reducing agent and conductive carbon material support. The formation of AuNPs was confirmed by UV–visible spectroscopy and transmission electron microscopy. It was demonstrated that after the nanocomposite immobilization on a substrate, the EHC material can be easily removed due to its outstanding solubility in water. This procedure was exemplified for the modification of a glassy carbon electrode, resulting in a bare AuNPs/GC electrode. The cyclic voltammetry was used to evaluate the effectiveness of AuNPs immobilization on the electrode and to track the dependence of the electroactive surface area and Au loading with the reaction mixture composition (HAuCl4/EHC). The potential of the AuNPs and nanocomposite-modified electrodes as sensor platforms for medical and biological applications was exemplified by their performance for the oxygen reduction reaction in a phosphate buffer saline solution. [Display omitted] •Carbon hydrophilic nanomaterial works itself as reducing agent for AuNPs.•Facile strategy to prepare a conductive AuNPs composite.•Elegant method to convert a nanocomposite modified electrode in a bare NPs/GC electrode.•Nanocomposite and nanoparticles modified electrodes were used for O2 sensing.