Used as a substrate in enzymatic assays, particularly for detecting esterase and cholinesterase activity in biological samples. It is also employed in histochemistry to identify enzyme distribution in tissues through colorimetric reactions, where enzyme hydrolysis releases 1-naphthol, which then couples with diazonium salts to form visible dyes. Additionally, it serves in pesticide toxicity testing due to its sensitivity to inhibition by organophosphorus and carbamate compounds. Its stability and clear reaction endpoint make it valuable in both clinical diagnostics and environmental monitoring.