Label-free electrochemical sensor to investigate the effect of tocopherol on generation of superoxide ions following UV irradiation

Abstract

BackgroundGeneration of reactive oxygen species (ROS), triggered by ultraviolet radiation (UVR), is associated with carcinogenesis of the skin. UV irradiation induced superoxide anion (O2•−) is the key ROS involved in the cellular damage. The cytoprotective efficacy of an unknown anti-oxidant compound can be evaluated by analyzing the production of O2•− from treated cells.MethodsIn this study, a glass carbon electrode functionalized with nanotube@DNA-Mn3(PO4)2 composite was applied to quantitative determination of generation of highly unstable O2•− from the melanoma A375 cell line following UVR(UV, UVA and UVB). In addition, the cytoprotective efficacy of anti-oxidant α-tocopherol was evaluated by quantifying the production of O2•−.ResultsThe results showed that, UVR triggers generation of O2•− in melanoma A375 cells, and α-tocopherol is effective in diminishing the production of O2•− following UV irradiation. By comparing the conventional cell-survival assays results, we found that our simple and quick electrochemical sensing method can quantify O2•− generation through the biological activity of an anti-oxidant compound (α-tocopherol).ConclusionOur label-free electrochemical quantification method for ROS (O2•− major) in cells facing UVR stress demonstrates its potential application for high-throughput screening of anti-oxidation compounds.