Electropolymerization of hydroxybenzene and aminobenzene isomers on platinum electrodes to assemble interference-free electrochemical biosensors

Hydroxybenzene and aminobenzene isomers have been electropolymerized on platinum electrodes together with oxidase enzymes for preparation and analytical evaluation of electrochemical biosensors. A conventional three electrode system was assembled for the electropolymerization of these compounds which led to the formation of poly(hydroxybenzene) and poly(aminobenzene). Different scan rates and scan ranges of potential were investigated and selected according to the monomer used. The time of electropolymerization was from 7 min to 4 h. All the electrodes with the polymer films formed were tested for H2O2 by cyclic voltammetry; Compounds as ascorbate, urate and acetaminophen, which are a common source of interferences in electrochemical biosensors analysis, based on H2O2 detection, were tested. Results showed an oxidation peak of H2O2 at the bare electrode and in all the electropolymerized probes, whereas for the interfering compounds the oxidation peak at electropolymerized probes was considerably reduced or not observed. When the electropolymerization was carried out in presence of the enzyme glucose oxidase, again the probe did not respond to the interferents, but gave a current signal to glucose in the range of 0.05 to 5 mmol/L.