Used in biochemical research as a substrate for enzymes like β-glucosidase, which hydrolyzes it to 4-nitrophenol and glucose. The amount of 4-nitrophenol produced, detectable by its yellow color via spectrophotometry, serves as an indicator of enzyme activity. It helps in studying enzyme activity and kinetics. Applied in assays to detect and measure enzyme presence and function. Useful in understanding carbohydrate metabolism and related pathways. Also employed in developing diagnostic tools for enzyme-related disorders, as well as in pharmacological research to study enzyme mechanisms and develop new drugs.