Enhancement effect of Brij-35 on the hemin-catalyzed fluorogenic reaction between hydrogen peroxide and N,N′-dicyanomethyl-o-phenylenediamine Original Research Article

The influence of various surfactants on the fluorogenic reaction of hydrogen peroxide (H2O2) oxidizing N,N′-dicyanomethyl-o-phenylenediamine catalyzed by hemin was systematically studied. The results showed that, in the presence of some surfactants, especially Brij-35, a non-ionic surfactant, the reaction rate and sensitivity were greater (6 times and more than 5 times greater than in its absence, respectively, for Brij-35). Linear ranges for hydrogen peroxide covered 1.8×10−9 to 1.8×10−5 M, three orders of magnitude wider than the system in the absence of Brij-35. Moreover, Brij-35 changed the optimum pH of the reaction from 11 to 10.5, but there was little difference in the fluorogenic reaction over the wide pH range of 8.5–11.0. Light scattering data proved that a change in the diameter of Brij-35 micelles was closely related to the activity change of hemin.