Detection of Ferric Ions In a Gram-Positive Bacterial Cell: Staphylococcus aureus

Authors

Erendra Manandhar, University of Southern Mississippi
Ashley D.G. Johnson, University of Southern MississippiFollow
William M. Matson, University of Southern Mississippi
Shelby D. Dickerson, University of Southern Mississippi
Gyan S. Sahukhal, University of Southern MississippiFollow
Mohamed O. Elasri, University of Southern MississippiFollow
Frank R. Fronczek, Louisiana State UniversityFollow
Peter J. Cragg, University of Brighton
Karl J. Wallace, University of Southern MississippiFollow

Document Type

Article

Publication Date

12-30-2020

Department

Chemistry and Biochemistry

School

Mathematics and Natural Sciences

Abstract

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 K_a = 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.

Publication Title

Journal of Coordination Chemistry

Volume

74

Issue

1

First Page

380

Last Page

401

Recommended Citation

Manandhar, E., 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