Nanocarbon and nanodiamond for high performance phenolics sensing

Phenolic compounds are pollutants of major concern, and effective monitoring is essential to reduce exposure. Electrochemical sensors offer rapid and accurate detection of phenols but suffer from two main shortcomings preventing their widespread use: electrode fouling and signal interference from co-existing isomers. Here we demonstrate a potential solution based on environmentally friendly and biocompatible carbon nanomaterials to detect monophenols (phenol and cresol) and biphenols (hydroquinone and catechol). Electrode fouling is tackled in two ways: by introducing electrochemically resistant nanodiamond electrodes and by developing single-use nanocarbon electrodes. We provide a comprehensive analysis of the electrochemical performance of three distinct carbon materials (graphene, nanodiamond and nanocarbon). Nanocarbon exhibits the lowest detection limit below 10−8 M, and one order of magnitude higher sensitivity than the other carbon nanomaterials. We detect co-existing phenol isomers with nanocarbon electrodes and apply it in river water and green tea samples, which may pave the way towards low-cost industrial scale monitoring of phenolic compounds