Sensors, Vol. 19, Pages 5458: A Novel Thiophene-Based Fluorescent Chemosensor for the Detection of Zn2+ and CN-: Imaging Applications in Live Cells and Zebrafish (Sensors)

A novel fluorescent turn-on chemosensor DHADC ((E)-3-((4-(diethylamino)-2-hydroxybenzylidene)amino)-2,3-dihydrothiophene-2-carboxamide) has been developed and used to detect Zn2+ and CN−. Compound DHADC displayed a notable fluorescence increase with Zn2+. The limit of detection (2.55 ± 0.05 μM) for zinc ion was far below the standard (76 μM) of the WHO (World Health Organization). In particular, compound DHADC could be applied to determine Zn2+ in real samples, and to image Zn2+ in both HeLa cells and zebrafish. Additionally, DHADC could detect CN− through a fluorescence enhancement with little inhibition with the existence of other types of anions. The detection processes of compound DHADC for Zn2+ and CN− were demonstrated with various analytical methods like Job plots, 1H NMR titrations, and ESI-Mass analyses.