A novel fluorescent method for determination of peroxynitrite using folic acid as a probe

A novel method for the determination of peroxynitrite using folic acid as a fluorescent probe is described. The method is based on the oxidation of the reduced, low-fluorescent folic acid by peroxynitrite to produce a high-fluorescent emission product. The fluorescence increase is linearly related to the concentration of peroxynitrite in the range of 3 × 10−8 to 5.0 × 10−6 mol L−1 with a correlation coefficient of 0.998, and the detection limit is 1 × 10−8 mol L−1. Interferences from some metal ions normally seen in biological samples, and also some anions structurally similar to peroxynitrite were studied. The optimal conditions for the detection of peroxynitrite were evaluated.