The development of sensitive and selective methods for detecting zinc ions holds significant research importance in both environmental and biol. contexts.Fluorescent probe methods outperform traditional detection methods in terms of sensitivity, selectivity, and real-time monitoring.In this study, we successfully synthesized a fluorescent chemosensor HL.It is derived from acylhydrazone Schiff base that features a straightforward synthesis, low toxicity and stable properties.The HL chemosensor was characterized using various spectroscopic techniques to confirm its structure and optical properties.Fluorescence spectroscopy anal. revealed that the HL chemosensor exhibits an obvious fluorescence turn-on response to zinc ions in aqueous medium., maintaining good selectivity even in the presence of various competing metal ions.The binding ratio of HL chemosensor to Zn2+ was determined to be 1:1 through UV-visible titration experiments, and this finding further supported by the crystal structure of the HL-Zn2+ complex.The results of fluorescence titration were also consistent with those from the UV-visible titration and crystallog. data.The as-prepared HL chemosensor exhibited a min. detection limit of 8.8 x 10-8 M, lower than that of most reported zinc ion fluorescence probes.A complexation constant of 2.6 x 105 M-1 based the Stern-Volmer equation indicates a strong coordination binding.Importantly, the exceptionally selective and sensitive HL chemosensor demonstrates chem. reversibility and can be recycled 5 times for reuse, significantly reducing the cost of the assay.This featured exptl. procedure, which employs Na2EDTA to eliminate or replace Zn2+, is an efficient, convenient, and gentle process compared to traditional methods involving heating, high temperatures, and washing.In particular, cytotoxicity tests showed that the chemosensor HL displayed low toxicity in Hela cells, confirming its suitability for detecting zinc ions in living cells.These indicate a promising application of this HL chemosensor in environmental monitoring and biol. research, and future exploration can delve into its potential for practical applications.