Investigation of the anthracene-nitroxide hybrid molecule as a probe for hydroxyl radicals

A new method for the determination of hydroxyl radicals is proposed. The me thod is based on the use of a hybrid molecule consisting of a fluorescent c hromophore, anthracene, and a nitroxide radical. In the hybrid molecule, th e nitroxide quenches the fluorescence of anthracene strongly. The reaction of hydroxyl radicals with dimethyl sulfoxide generates quantitatively methy l radicals, which then combine with the nitroxide moiety of the hybrid mole cules to result in an increase in the fluorescence intensity. The fluoresce nce increase is proportional to the concentration of hydroxyl radicals. The proposed method is capable of detecting hydroxyl radicals generated in the Fenton system. It is a simple and sensitive technique for the determinatio n of hydroxyl radicals.