Study and application of perturbation of peroxynitrite on peroxidase–oxidase oscillation

Peroxynitrite was one of the important reactive oxygen species (ROS) which have been focused for many years. Peroxynitrite is an extremely strong and reactive oxidant which can cause many diseases linked to inflammatory processes and autoimmune diabetes, etc. ROS can significantly react with peroxidase and nicotinamide adanine dinucleotide (NADH) which is linked to numerous biological processes. NADH, NAD and horseradish peroxidase (HRP) were included in peroxidase–oxidase (PO) oscillation, dissolved oxygen was concerned with the oscillation and many ROS intermediates came into being in PO oscillation which was sensitive to the perturbation of ROS. The influence of peroxynitrite (ONOO−) on this oscillation system was investigated. It was found that the oscillation amplitude increased when the system was perturbed with peroxynitrite. There was a linear relationship between the increment ratio in the oscillation amplitude and perturbing peroxynitrite concentration in the range 2.50 × 10−8 to 1.56 × 10−6 mol/L. And further experimental results revealed that amplitude increasing may be caused by the effect of peroxynitrite on HRP. Based on this phenomenon, a highly sensitive method for the determination of peroxynitrite was developed.