A novel benzothiazole-based fluorescent probe for continuous detection of Cu2+/S2− and its application in cell imaging.

• A novel fluorescent probe DYH was fabricated and characterized. • In CH 3 CN/HEPES (7/3, v/v, HEPES 100 mM pH = 7.3), the probe DYH can continuously detect Cu2+ and S2−. • DYH has a wide linear range and low detection limit for Cu2+ (0.56 μM) and S2− (0.67 μM). • DYH was found useful for imaging of Cu2+ and S2− in living cells. In this paper, a fluorescent probe methyl(E)-2-(3-(benzo[ d ]thiazol-2-yl)-2‑hydroxy -5-methylbenzylidene) hydrazine-1-carboxylate (DYH) based on benzothiazole was designed and synthesized. The characterization involved NMR, HRMS, and crystal structure analysis. In case of the existence of other competing cations, the probe DYH showed high-affinity for Cu2+, and the resultant DYH Cu2+ showed exceptional capacity to recognize S2− in CH 3 CN/HEPES (7/3, v/v, HEPES 0.1 M, pH = 7.3). The detection limits of DYH for Cu2+ and DYH Cu2+ for S2− were 0.56 μM and 0.67 μM, respectively. It was determined that the binding stoichiometry between the DYH and Cu2+, as well as DYH Cu2+ and S2−, was 1:1 according to the job's curve. The pH of the probe and complex was stable between 4 and 10. Colorimetric experiments of the probe DYH were conducted using test paper as a carrier. Additionally, DYH was used for fluorescence imaging of Cu2+ and S2− in Hela cells with poor cellular toxicity and good cell permeability. [Display omitted] [ABSTRACT FROM AUTHOR]