Detection of ferric ions in a gram-positive bacterial cell: Staphylococcus aureus. Issue 1 (23rd December 2020)

• Record Type: Journal Article
• Authors: Manandhar, Erendra; Johnson, Ashley D. G.; Watson, William M.; Dickerson, Shelby D.; Sahukhal, Gyan S.; Elasri, Mohamed O.; Fronczek, Frank R.; Cragg, Peter J.; Wallace, Karl J.
• Is Part Of: Journal of coordination chemistry. Volume 74:Issue 1/3(2021)
• Page Start: 380
• Page End: 401
• Publication Date: 2020-12-23
• Subjects: Ferric ions -- sensing -- gram-positive bacteria -- coordination -- molecular probes; Coordination compounds -- Periodicals; 541.2242
• DOI: 10.1080/00958972.2020.1868042
• Languages: English
• ISSNs: 0095-8972

Abstract

Abstract: A rhodamine-based chemosensor was synthesized and found to selectively bind ferric ions over other metal ions (Na +, K +, Ca 2+, Mg 2+, Fe 2+, Zn 2+, Cd 2+, Co 2+, Hg 2+ Cr 3+, Al 3+ ) in an organic-aqueous mixture (CH3 CN-MES). Upon addition of ferric ions, the spirolactam ring opens, producing a visual color change and a fluorescence intensity increase, i.e. a "turn on" optical response at 577 nm is observed. The chemosensor coordinates to ferric ions in 1:1 stoichiometry with a calculated K a = 3.5 × 10 4 mol⋅dm −3 by fluorescence spectroscopy and a LoD of 27 ppb. The chemosensor was reversible upon addition of the Fe 3+ chelator desferrioxamine. One- and two-dimensional NMR experiments with Al 3+ ions aided in understanding of the coordination environment of the ferric ion with the chemosensor, which were confirmed by molecular modeling calculations. X-ray quality crystals of the chemosensor were obtained, and the solid-state structure is reported. Confocal microscopy was used to detect free ferric ions in Staphylococcus aureus . Graphical Abstract: