Detection of Ferric Ions In a Gram-Positive Bacterial Cell: Staphylococcus aureus
Chemistry and Biochemistry
Mathematics and Natural Sciences
A rhodamine-based chemosensor was synthesized and found to selectively bind ferric ions over other metal ions (Na+, K+, Ca2+, Mg2+, Fe2+, Zn2+, Cd2+, Co2+, Hg2+ Cr3+, Al3+) in an organic-aqueous mixture (CH3CN-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 Ka = 3.5 × 104 mol⋅dm−3 by fluorescence spectroscopy and a LoD of 27 ppb. The chemosensor was reversible upon addition of the Fe3+ chelator desferrioxamine. One- and two-dimensional NMR experiments with Al3+ 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.
Journal of Coordination Chemistry
Johnson, A. D.,
Matson, W. M.,
Dickerson, S. D.,
Sahukhal, G. S.,
Elasri, M. O.,
Fronczek, F. R.,
Cragg, P. J.,
Wallace, K. J.
(2020). Detection of Ferric Ions In a Gram-Positive Bacterial Cell: Staphylococcus aureus. Journal of Coordination Chemistry, 74(1), 380-401.
Available at: https://aquila.usm.edu/fac_pubs/18508