A dual-response fluorescent probe for Al3+ and Zn2+ in aqueous medium based on benzothiazole and its application in living cells

Abstract A new benzothiazole-based fluorescent chemosensor (BZDM), namely 2-amino-3-(((E)-3-(benzo[d]thiazol-2-yl)-2-hydroxy-5-methylbenzylidene)amino)maleonitrile, has been designed and synthesized for detection of Al3+/Zn2+ in aqueous medium. The sensing behavior displayed that BZDM possessed an excellent selectivity towards Al3+/Zn2+ with a distinct fluorescence enhancement in DMSO/Tris-HCl buffer solution. The binding stoichiometry was determined to be 1: 1 between BZDM and Al3+/Zn2+ according to Job’s plot method and NMR analysis. The sensing of Al3+/Zn2+ was almost free from interference of other relevant metal ions. Under optimal conditions, the LOD value for Al3+ and Zn2+ was found to be 7.06 μM and 2.98 μM, separately. Notably, the probe was found to have good biological compatibility and was employed to detect Al3+/Zn2+ in living Hela cells.