Electrochemical detection of DNA damage induced by acrylamide and its metabolite at the graphene-ionic liquid-Nafion modified pyrolytic graphite electrode

Abstract

A new electrochemical biosensor for directly detecting DNA damage induced by acrylamide (AA) and its metabolite was presented in this work. The graphene-ionic liquid-Nafion modified pyrolytic graphite electrode (PGE) was prepared, and then horseradish peroxidase (HRP) and natural double-stranded DNA were alternately assembled on the modified electrode by the layer-by-layer method. The PGE/graphene-ionic liquid-Nafion and the construction of the (HRP/DNA) n film were characterized by electrochemical impedance spectroscopy. With the guanine signal in DNA as an indicator, the damage of DNA was detected by differential pulse voltammetry after PGE/graphene-ionic liquid-Nafion/(HRP/DNA) n was incubated in AA solution or AA + H 2O 2 solution at 37 °C. This method provides a new model to mimic and directly detect DNA damage induced by chemical pollutants and their metabolites in vitro. The results indicated that, in the presence of H 2O 2, HRP was activated and catalyzed the transformation of AA to glycidamide, which could form DNA adducts and induce more serious damage of DNA than AA. In order to further verify these results, UV–vis spectrophotometry was also used to investigate DNA damage induced by AA and its metabolites in solution and the similar results were obtained.