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

Abstract

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

Development of Surface‐Modified Microelectrode Arrays for the Electrochemical Detection of Dihydrogen Phosphate

“…However, selectivity data for these types of reagents are available in the literature, but on conventionally-sized electrodes, not MEAs [7,8,27]. On the other hand, electrochemical studies involving redox hosts for the binding and sensing of anionic species in aqueous environments are unusual [6], as the water interacts with the receptors, solvating them and shielding them from the species to be detected. In aqueous media, the poly(amidoferrocene) films show no response to the various oxo-anions.…”

“…Additionally, in protic and polar solvents, the ferrocenylalkylammonium compounds, either in solution [5] or immobilized on an electrode surface [7], exhibit no anion recognition. However, Moutet and co-workers [6] reported the electrochemical sensing of anions in water using ferrocene-containing viologen receptors. This approach demonstrated the selective voltammetric sensing of ATP 2À in water, which is not only based on the strong electrostatic interactions between the anions and the positive-charged bipyridinium fragments (plus interactions due the to ferricinium), but also based on the specific charge transfer between the p-donor anion and the electron-acceptor viologen groups [6].…”

“…However, Moutet and co-workers [6] reported the electrochemical sensing of anions in water using ferrocene-containing viologen receptors. This approach demonstrated the selective voltammetric sensing of ATP 2À in water, which is not only based on the strong electrostatic interactions between the anions and the positive-charged bipyridinium fragments (plus interactions due the to ferricinium), but also based on the specific charge transfer between the p-donor anion and the electron-acceptor viologen groups [6]. Furthermore, the recognition performance was observed to be improved using poly(ferroceneviologen) film electrodes as these create a macromolecular effect that improves the sensing.…”

“…A number of reports have shown that species containing metallocene hosts are useful in redox electrochemical recognition of anionic species [3 -11] of biological relevance [10] such as H 2 PO À 4 [8 -11], P 2 O 4À 7 [9], HSO À 4 [8 -10], ATP 2À [6,8]. Receptors containing ferrocenyl groups are of interest as they exhibit interesting anion recognition effects due to switch-on of a strong electrostatic interaction upon oxidation of ferrocene to ferricinium.…”

Metallodendritic Exo-Receptors for the Redox Recognition of Oxo-Anions and Halides

“…Some challenges remain: for instance chiral recognition and simultaneous recognition of both cations and anions [for instance with cobaltocenyl dendrimers [8-14, 104, 105]]; the recognition of biologically important anions in water has still not been successfully achieved despite interesting recent attempts [106,107]. A higher level of sophistication in the molecular design of the potential receptors and sensors is now clearly required for further progress in these directions.…”