3-(10′-Phenothiazinyl)propionic acid is a potent primary enhancer of peroxidase-induced chemiluminescence and its application in sensitive ELISA of methylglyoxal-modified low density lipoprotein

Using a full factorial design the optimization of experimental conditions of enhanced chemiluminescence reaction (ECR) catalyzed by horseradish peroxidase (HRP) in the presence of 3-(10′-phenothiazinyl)propionic acid (PPA) as a primary enhancer was performed. The effect of concentrations of PPA, hydrogen peroxide, MORPH, luminol, and Tris on a ratio of peroxidase-catalyzed CL to background was studied. The detection limit value of HRP in ECR with PPA was 0.09 pM. Using PPA the ultra-sensitive chemiluminescent ELISA for determination of methylglyoxal-modified low density lipoprotein was developed. The detection limit value for the developed method was 0.5 ng mL−1. The obtained results open up very promising perspectives for using PPA to improve the sensitivity of enzyme immunoassay kits.