Three-Dimensionally Extended Host Electrodes for Biosensor Applications

Abstract

A new concept of three-dimensionally extended host electrodes is proposed with the fabrication and applications of fluorine-doped tin oxide (FTO) nanorod array based host electrodes as an example. The FTO nanorod arrays were grown on top of commercial FTO glass through a vapor-liquid-solid process by using Au nanocrystals as the anisotropic growth catalyst, tin powders as the precursor, and NH4F as the fluorine source. This three-dimensionally extended FTO nanostructure was then decorated with Pt nanocrystals, using a polyol method, to serve as a non-enzymatic sensing electrode for H2O2. These FTO nanorods not only offer greatly enlarged sensing areas and fast charge transport channels, but also significantly enhance the hydrophilicity of the electrode, all of which are beneficial for the electrochemical sensing of aqueous samples. A two order of magnitude improvement in sensitivity toward H2O2 over the plain commercial FTO glass was achieved, reaching a high sensitivity value of 543mAM-1cm2. Extend a warm welcome: Three-dimensionally extended host electrodes drastically enhance the sensitivities of non-enzymatic hydrogen peroxide sensing by two orders of magnitude.