Detection of esterase activity by chromogenic and fluorogenic probe based on an O-nitrobenzoxadiazole (O-NBD) unit

Abstract We designed a conjugated molecule bearing an O -nitrobenzoxadiazole ( O -NBD) unit and an acetylated trimethyl lock as a chromogenic and fluorogenic probe for the detection of esterase activity. The designed molecule was briefly synthesized from a commercially available compound in two steps. Several experiments revealed that the conjugated molecule serves as a sensitive chromogenic and fluorogenic probe for the detection of porcine liver esterase activity. Mechanistic studies indicated that an intramolecular O - to N -NBD migration is involved in the chromogenic/fluorogenic phenomena. The results here would be helpful for designing other O -NBD-based chromogenic/fluorogenic probes in future.