Used as a substrate in enzymatic assays, particularly for detecting peroxidase activity. It is widely applied in biochemistry and molecular biology research to measure the presence and activity of enzymes like horseradish peroxidase. ABTS is also utilized in antioxidant capacity assays, where it helps quantify the ability of compounds to scavenge free radicals. Its color change upon oxidation makes it a valuable tool in spectrophotometric analysis. Additionally, it is employed in diagnostic kits for detecting biomarkers in clinical and environmental samples.