Label-Free Electrochemical Biosensors to Evaluate the Antioxidant Effect of Tocopherol in Ultraviolet Radiation.

Electrochemical biosensors offer a sensitive, specific, and rapid detection platform for in situ real-time monitoring of intracellular and extracellular metabolites. These sensors have been widely used to evaluate the efficacy of preclinical drugs, especially for natural products with antioxidant potency. Ultraviolet (UV) radiation causes oxidative stress in cells and induces cells to release reactive oxygen species. Tocopherol is a fat-soluble vitamin found in vegetable oils as well as in grains, seeds, and nuts, which plays an important protective role as an antioxidant in resisting oxidative stress caused by UV radiation. Here, we describe a protocol using a glass carbon electrode functionalized with nanotube@DNA-Mn3(PO4)2 composite to monitor and quantify the production of superoxide ions in UV-irradiated melanoma cells in the presence or absence of tocopherol. This study demonstrates the advantages and potential application of label-free electrochemical sensors in the measurement of natural antioxidants from plant materials.