Used in biochemical research as a substrate for detecting cholinesterase enzyme activity. When the enzyme cleaves the compound, it releases 4-nitrophenol, which produces a yellow color that can be measured spectrophotometrically. This reaction is useful for monitoring enzyme kinetics, screening inhibitors, and assessing neurotoxic exposure in clinical or environmental samples. Also employed in the development of biosensors and diagnostic assays for nerve agent detection due to its sensitivity to organophosphate compounds.