An On–Off–On Fluorescence Probe Based on Coumarin for Cu2+, Cysteine, and Histidine Detections. Issue 7 (July 2019)

• Record Type: Journal Article
• Authors: Xie, Ya; Yan, Liqiang; Li, Jianping
• Is Part Of: Applied spectroscopy. Volume 73:Issue 7(2019)
• Page Start: 794
• Page End: 800
• Publication Date: 2019-07
• Subjects: Fluorescence probe -- Cu2+ -- cysteine -- histidine; Spectrum analysis -- Periodicals; 543.505
• DOI: 10.1177/0003702818821329
• Languages: English
• ISSNs: 0003-7028

Abstract

A simple coumarin-based Schiff base (probe L) was successfully developed. It showed strong green fluorescence emission at 527 nm with a 70.3% of fluorescence quantum efficiency (ΦF ). However, after the addition of common metal ions, probe L can only combine with Cu 2+ ions and displayed significant fluorescence quenching of > 96.2% (ΦF = 2.7%) due to the paramagnetic quenching action from Cu 2+ . Conversely, by the coordination action of cysteine (Cys) and histidine (His), the quenching fluorescence of the complex (L-Cu 2+ ) between probe L and Cu 2+ ions was recovered mostly because the Cys and His can usurp Cu 2+ of L-Cu 2+ and led to the liberation of probe L. Based on the fluorescence changes of probe L with the actions of Cu 2+, Cys, and His, an on–off–on reversible fluorescence probe for sensitive and specific monitoring Cu 2+, Cys, and His has been prepared. More importantly, the probe L and L-Cu 2+ ensemble can be used, respectively, to test Cu 2+ and Cys/His in live cells and human urine samples with great reliability.