Versatile Electrochemical Platform for the Determination of Phenol-like Compounds Based on Laccases from Different Origins

Simple and fast methods for the monitoring of phenol-like compounds are relevant in diverse fields ranging from waste management to neurosciences. Laccases are copper-containing enzymes, which, depending on their origin, are able to oxidize different phenol compounds at different pH conditions. Through adequate laccase immobilization, disposable screen printed electrodes can be used as interphase to build amperometric phenol sensors. In this work three different laccases were studied for the determination of phenol-like compounds, two of them are isoenzymes from Trametes trogii and the third one from Rhus vernicifera. Their immobilization on screen printed electrodes is presented for the construction of amperometric sensors. The electrode substrate is composed by graphite screen printed electrodes modified with carbon nanotubes and silica microspheres where, depending on the application, one of the three laccases is adsorbed. As each laccase shows an optimum working pH, they were conveniently selected to determine dopamine at physiological pH and catechol at acid pH. Determinations in the micromolar range were possible in both cases. Chronoamperometry shows to be an effective technique for their determinations, simpler than other electrochemical methods already presented in the literature.