Spectrofluorometric Determination of Superoxide Anion Radicals and Superoxide Dismutase Activity Using a 2-(2-Thienyl)Benzothiazoline Probe

A new fluorescent probe, 2-(2-thienyl)benzothiazoline was synthesized. Its structure was characterized with elemental analysis, IR and 1H NMR. The fluorescent probe can be oxidized by to form a less fluorescent product. Based on this reaction, a spectrofluorometric method was developed to determine the content of superoxide anion radicals and superoxide dismutase activity. There was a good linear relationship with a correlation coefficient 0.9996 between the scavenging percentage of and SOD activity. The method was simple, selective, and sensitive. It was successfully applied to the determination of SOD activity in garlic and onion samples.