Olivier Reynes

Complexation and electrochemical sensing of anions by amide-substituted ferrocenyl ligands

New amide-containing ferrocenyl ligands, L1–5, were prepared and the voltammetric and 1H NMR investigations of anion binding were carried out in organic media. The electrochemical recognition ability of L1–5 towards F−, HSO4−, H2PO4− and ATP2− is based on the synergy between H-bonding to amide protons in anion complexation to reduced, neutral ligands and ion-pairing interactions developed with the oxidized, cationic form of the ligands. The strength of the anion–ligand interactions depends on the number of ferrocene centers and amide groups in the receptor, and on the accessibility of the binding sites. Clear two-wave cyclic voltammetry features allowed the amperometric titration of H2PO4− and ATP2− by ligands L4 and L5 built from a cyclotriveratrylene structural unit, and containing a combination of three ferrocene centers with three (L4) or six (L5) amide groups.

(Ferrocenylmethyl)trimethylammonium cation: a very simple probe for the electro-chemical sensing of dihydrogen phosphate and ATP anionsElectronic supplementary information (ESI) available: cyclic voltammograms of 1 in the presence of increasing amounts of ATP2– or HSO4–. See http://www.rsc.org/suppdata/nj/b1/b107713a/

By virtue of strong ion-pairing interactions that are reinforced following its oxidation to the ferrocinium form, (ferrocenylmethyl)trimethylammonium cation is able to electrochemically sense dihydrogen phosphate and ATP anions in organic electrolytes; clear two-wave voltammetry features allow their amperometric titration by this very simple derivative of ferrocene.

Redox sensing of anions in pure aqueous environment by ferrocene-containing 4,4′-bipyridinium-based receptors and polymer films

Selective voltammetric sensing of ATP(2-) anions in water was achieved using ferrocene-viologen based redox active receptors and related polymer films.

Amplification upon polymerization of the electrochemical anion sensing properties of an amidoferrocene monoreceptor molecule

Abstract Oxidative electropolymerization of pyrrole-substituted monoamidoferrocene 1 yields redox polymer films showing marked electrochemical sensing properties towards H 2 PO 4 − and ATP 2− anions in organic electrolytes, as demonstrated by differential pulse voltammetry experiments. This behavior contrasts with the poor sensing properties of monomer 1 .

EPR spectroelectrochemical investigation of guanine radical formation and environment effects.

Guanine radical detection was carried out by a new convenient and efficient method coupling electron paramagnetic resonance spectroscopy and indirect electrooxidation of guanine in different biological environments, from the free nucleotide to several types of DNA substrates. Compared to the widely used photoirradiation method, this method appeared more selective in the choice of the electrochemical mediator. Carried out in presence of a ruthenium mediator and PBN as spin trap, this method revealed two types of EPR spectra depending of the environment of the guanine radical. Both EPR spectra show the trapping of the neutral guanine radical G(-H)(•) obtained after fast deprotonation of the radical cation G(•+). However, they differ by the atom where the trapped radical is centered. This difference highlights the structural dependency of the environment on the nature of the radical formed. This work gave the evidence of an innovative method to detect in situ the guanine radical.