Highly sensitive fluorescent bioassay of 2,3,7,8-tetrachloro-dibenzo-p-dioxin based on abnormal expression of cytochrome P450 1A2 in human cells

Highlights: • HBMN demonstrated ca. 60 times higher affinity to CYP1A2 than the-state-of-art 7-ER probe. • The in vitro bioassay was constructed by HBMN probe in human cells. • The sensing strategy had 10 times improved sensitivity TCDD detection compared to previous reports using 7-ER probe. • Based on HBMN, the higher abnormal expression of CYP1A2 by TCDD induction in human hepatic cells was found than that in lung cells. -- Abstract: Current in vitro bioassays of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, a major threat carcinogen) are relied on murine cells and fluorescent probe 7-ethoxyresorufin (7-ER), in which TCDD mostly causes abnormal expression of cytochrome P450 1A1 (CYP1A1). However, for human cells, TCDD mainly leads to a distinct abnormal expression of cytochrome P450 1A2 (CYP1A2). The poor response of 7-ER to CYP1A2 limits the traditional bioassay for human cells. Herein, we report a fluorescent probe N-(3-hydroxybutyl)-4-methoxy-1,8-naphthalimide (HBMN) for in vitro bioassay of TCDD with human cells. HBMN had ca. 60 times higher affinity to CYP1A2 than 7-ER. As such, the sensing sensitivity increased by 10 times, and different expression of CYP1A2 by TCDD induction in different human cells was found. Besides, HBMN was also feasible in rapid screening of TCDD concentration by naked eye. It would open a new way to highly sensitive detect TCDD and understand the pathogenesis of TCDD in different human organs.