title: Multimode selective detection of mercury by chiroptical fluorescent sensors based on methionine/cysteine.
abstract: Two multimode Hg(II) sensors, L-MethBQA and L-CysBQA, were obtained by fusing methionine or S-methyl cysteine, into a bis-quinolyl amine-based chiral podand scaffold. Quinolyl groups serve as the fluorophore and possess nitrogen lone pairs capable of chelating metal ions. On exposure to Hg(2+) or Zn(2+), these sensors show signal enhancement in fluorescence. However, Cu(2+) quenches their fluorescence in 30:70 acetontrile/water. L-CysBQA complexes with Hg(2+), producing an exciton-coupled circular dichroism spectrum with the opposite sign to the one that is produced by Cu(2+) or Zn(2+) complexation. L-CysBQA binds Hg(2+) more strongly than Zn(2+) and is shown to differentiate Hg(2+) from other metal ions, such as Zn(2+), Cu(2+), Ni(2+), and Pb(2+), exceptionally well. The synergistic use of relatively soft sulfur, quinoline-based chiral ligands and chiroptically enhanced fluorescence detection results in high sensitivity and selectivity for Hg(2+).
authors.affiliation: Department of Chemistry and Physical Sciences, Pace University, New York, New York.
authors.forename: Patrick
authors.initials: P
authors.lastname: Carney
authors.forename: Steven
authors.initials: S
authors.lastname: Lopez
authors.forename: Amanda
authors.initials: A
authors.lastname: Mickley
authors.forename: Kirill
authors.initials: K
authors.lastname: Grinberg
authors.forename: Wenyao
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Dai