Used as a key component in colorimetric assays for the detection of oxidizing agents and peroxidase activity. It couples with phenolic compounds or aromatic amines in the presence of hydrogen peroxide and peroxidase enzymes to form intensely colored azo dyes, making it valuable in diagnostic reagents and clinical testing. Commonly applied in glucose, cholesterol, and uric acid test kits where enzymatic reactions generate hydrogen peroxide. Also utilized in environmental and food industry testing for monitoring oxidative processes. Its high sensitivity and stable color development make it suitable for both manual and automated analytical systems.