Sensitive Fluorescent Assay for Determination of Cu2+ in Aqueous Solution Using Isorhamnetin-β-cyclodextrin Inclusion

Publication date: June 2019Source: Chinese Journal of Analytical Chemistry, Volume 47, Issue 6Author(s): Shi-Long YANG, Wei-Na JIANG, Ying TANG, Li XU, Bu-Hong GAO, Hai-Jun XUAbstractA fluorescent probe based on isorhamnetin (Iso)-cyclodextrin (CD) inclusion for detecting Cu2+ was synthesized. A major fluorescence emission peak at 542 nm was observed for isorhamnetin (Iso) in buffer solution (pH 7.40) when the excitation wavelength was 390 nm. It was surprisingly found that (2-hydroxypropyl)-β-cyclodextrin (β-CD) could enhance the fluorescence intensity of Iso, and the major fluorescence peak was shifted to 557 nm. UV-vis spectrum showed that the Iso-β-CD system was formed by hydrogen bond and hydrophobic interaction. And the fluorescence intensity of Iso-β-CD system was stronger and more stable compared with Iso. Further study indicated that Iso-β-CD system had good selectivity and sensitivity toward Cu2+. When Cu2+ was added, the fluorescent emission intensity of Iso-β-CD system was quenched, while other metal ions could not bring about obvious change, which meant that the Iso-β-CD system had good selectivity toward Cu2+. The fluorescence titration spectra indicated that the concentration of Cu2+ was inversely proportional to fluorescence intensity, and fluorescence emission intensity was linearly correlated with the concentration of Cu2+ in the range of 0.05–6.0 μM. The calibration equation was y = −11.66x + 781.13 (R2 = 0.996), with a limit of detection of 0.0...
Source: Chinese Journal of Analytical Chemistry - Category: Chemistry Source Type: research