Study of nitroxide-linked naphthalene as a fluorescence probe for hydroxyl radicals

A novel technique for the determination of hydroxyl radical is described. The method employed the reaction of hydroxyl radical with dimethyl sulfoxide quantitatively to generate a methyl radical, which then coupled with nitroxide-linked naphthalene and led to a large increase in fluorescence intensity. The fluorescence increment was proportional to the concentration of hydroxyl radicals down to 1×10-7moll-1. The proposed method was demonstrated to be capable of detecting hydroxyl radicals generated in Fenton systems. It proved to be a simple and sensitive technique for the determination of hydroxyl radicals.