A Pencil Graphite Electrode (PGE) is herein disclosed. The electrode is characterized by a reduced content in graphite and an increased content in clay of the composite material composing it compared to the prior art PGEs. In particular, the PGE according to the invention is characterized by a clay/graphite ratio of at least 0.4. The PGE has a lower tendency to show a fouling effect when used in electrochemical analyses, particularly of phenolic compounds such as paracetamol and propofol present in a sample. Sensors comprising the PGE of the invention, as well as methods for using thereof, are also herein disclosed.