Luminol Luminescence Induced by 2,2'-Azo-Bis(2-Amidinopropane) Thermolysis

2-2'-Azo-bis(2-amidinopropane) thermolysis induces luminol luminescence. The luminescence intensity is quenched by SOD, catalase, Trolox and human blood serum. However, the time course of the light intensity profile is different for the different additives. In particular, the quenching efficiency of Trolox and human blood serum decreases with time after addition. Double quenching experiments show that SOD and Trolox are not competitive quenchers, while a simple competition can be established between Trolox and human blood serum in trapping a common intermediate. From the kinetic analysis of the data it is concluded that, at least at low additive concentrations, Trolox scavenges a luminol derived radical. Higher concentrations of Trolox or human blood serum produce induction times that are proportional to the additives concentrations. The possibility of employing luminol luminescence in the evaluation of TRAP levels and the capacity of biological samples to scavenge free radicals is discussed.