Mercury

Chemical Speciation of MeHg+ and Hg2+ in Water Solutions and HEK Cells Nuclei by means of DNA Interacting Fluorogenic Probes
  • Borja Díaz de Greñu, José García-Calvo, José V. Cuevas, Gabriel García-Herbosa, Begoña García, Natalia Busto, Saturnino Ibeas, Tomás Torroba
    Department of Chemistry, Faculty of Science, University of Burgos, 09001 Burgos, Spain
  • Blanca Torroba, Antonio Herrera, Sebastian Pons
    Molecular Biology Institute of Barcelona, Barcelona Science Park, 08028 Barcelona, Spain

Chem. Sci. 20156, 3757–3764

mercury_1

 

  • Borja Díaz de Greñu, José García-Calvo, José V. Cuevas, Gabriel García-Herbosa, Begoña García, Natalia Busto, Saturnino Ibeas, Tomás Torroba, Blanca Torroba, Antonio Herrera, Sebastian Pons

cbr_1Selected new fluorogenic probes that interact in different ways with Hg2+ and MeHg+ have been prepared and used for the chemical speciation of both cations in water solutions as well as in HEK293 cells.

Chem. Sci. 20156, 3757–3764

 

Observable colours under 366 nm UV light. The samples contain BD116 (upper) or BD119 (down) 10-4 M solutions in MeOH/H2O 20:80 with 2 equivalents of common cations, 5×10-3 M in water.

From left to right: Probe, H2O, Ag+, Ni2+, Sn2+, Cd2+, Zn2+, Pb2+, Cu2+, Fe3+, Sc3+, Al3+, Hg2+, Au3+.

Inset: BD116, 10-4 M, MeCN/H2O 20:80; BD119, 10-4 M, MeCN/H2O 40:60.

From Left to right: Probe, H2O, Hg2+, MeHg+ (2 equivalents)

cbr_2

Emission intensity spectra (λexc = 350 nm) and titration profile (λem = 480 nm) of BD116, 2.5 × 10-5 M in MeOH:H2O 20:80, with several additions of (A) Hg2+ or (B) MeHg+. The captions show the equivalents of cation for each curve; (C) Job’s plots of the complexes (1) BD116/Hg2+ and (2) BD116/MeHg+ (λexc = 350 nm) in MeOH:H2O 20:80.

cbr_3

T-Jump kinetic curve (A) BD116/Hg2+, lexc = 350 nm, lem = 460 nm

(B) BD116/MeHg+, lexc = 350 nm, lem = 460 nm

(C) Effect of the [Hg2+] + [P] and (D) [MeHg+] + [P] equilibrium concentrations on 1/τ. Continuous line is the linear fitting. Solvent MeOH:water 20:80

Fluorescence binding isotherm for (A) BD116/Hg2+ and (B) BD116/MeHg+ systems, lexc = 350 nm, lem = 460 nm. The thermodynamic values obtained for K were nearly identical to those from T-jump measurements

 cbr_4

Confocal fluorescence imaging of HEK293 cells in the presence of BD116 and Hg2+ 300 µM.

Upper left: Cells under visible light. Down left: Overlay maximum UV-Vis light. Down center: BD116 only. Right: BD116 in the presence of 300 µM Hg(II)

cbr_9

Confocal fluorescence imaging of HEK293 cells incubated in the presence of JG45 and MeHg+ 400 µM. Upper left: Cells under visible light. Down left: Overlay maximum UV-Vis light. Down center: cells with JG45 only. Right: cells with JG45 and 400 µM MeHg(II)

cbr_10