Jolly Kaushal, Sain Singh, Heena, Saakshi Saini, Partha Roy
{"title":"An easily synthesizable naphthalene-based sensing platform for Al<sup>3+</sup> and Zn<sup>2+</sup> ions: theoretical insights and live cells imaging.","authors":"Jolly Kaushal, Sain Singh, Heena, Saakshi Saini, Partha Roy","doi":"10.1039/d5ay00044k","DOIUrl":null,"url":null,"abstract":"<p><p>A new naphthalene-derived Schiff base probe, 1-((2-(diphenylphosphino)ethylimino)methyl)naphthalen-2-ol (HL), has been demonstrated for fluorometric detection of Al<sup>3+</sup> and Zn<sup>2+</sup> ions. HL was characterized by elemental analysis, FT-IR, NMR, UV-Vis, fluorescence, and ESI-MS analyses. It exhibited high sensitivity and selectivity toward Al<sup>3+</sup> and Zn<sup>2+</sup> ions in a semi-aqueous medium (CH<sub>3</sub>CN-H<sub>2</sub>O; 4 : 1, v/v), remaining unaffected by other competing metal ions. As a 'turn-on' fluorogenic probe, HL displayed strong emission enhancements at 430 nm and 450 nm (<i>λ</i><sub>ex</sub> 300 nm) upon the addition of Al<sup>3+</sup> and Zn<sup>2+</sup> ions, respectively, with detection limits of 0.62 μM for Al<sup>3+</sup> and 0.54 μM for Zn<sup>2+</sup>. The addition of Al<sup>3+</sup> caused <i>ca.</i> 20 nm blue-shift in emission and absorption maxima of HL due to strong complex formation. The calculated binding constant values were found to be 1.39 × 10<sup>3</sup> M<sup>-1</sup> and 4.78 × 10<sup>3</sup> M<sup>-1</sup>, respectively, for Al<sup>3+</sup> and Zn<sup>2+</sup> ions. Job's plot, NMR, ESI-MS, and density functional theory (DFT) studies supported the metal ion binding mechanism with 1 : 1 stoichiometry. Fluorescence imaging experiments further revealed HL's ability to detect intracellular Al<sup>3+</sup> in live cells with very low cytotoxicity, highlighting its potential as a selective chemosensory probe.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7000,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Analytical Methods","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d5ay00044k","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
A new naphthalene-derived Schiff base probe, 1-((2-(diphenylphosphino)ethylimino)methyl)naphthalen-2-ol (HL), has been demonstrated for fluorometric detection of Al3+ and Zn2+ ions. HL was characterized by elemental analysis, FT-IR, NMR, UV-Vis, fluorescence, and ESI-MS analyses. It exhibited high sensitivity and selectivity toward Al3+ and Zn2+ ions in a semi-aqueous medium (CH3CN-H2O; 4 : 1, v/v), remaining unaffected by other competing metal ions. As a 'turn-on' fluorogenic probe, HL displayed strong emission enhancements at 430 nm and 450 nm (λex 300 nm) upon the addition of Al3+ and Zn2+ ions, respectively, with detection limits of 0.62 μM for Al3+ and 0.54 μM for Zn2+. The addition of Al3+ caused ca. 20 nm blue-shift in emission and absorption maxima of HL due to strong complex formation. The calculated binding constant values were found to be 1.39 × 103 M-1 and 4.78 × 103 M-1, respectively, for Al3+ and Zn2+ ions. Job's plot, NMR, ESI-MS, and density functional theory (DFT) studies supported the metal ion binding mechanism with 1 : 1 stoichiometry. Fluorescence imaging experiments further revealed HL's ability to detect intracellular Al3+ in live cells with very low cytotoxicity, highlighting its potential as a selective chemosensory probe.