Solvent Effects in Halogen and Hydrogen Bonding Mediated Electrochemical Anion Sensing in Aqueous Solution and at Interfaces.

Abstract

Sensing anionic species in competitive aqueous media is a well-recognised challenge to long-term applications across a multitude of fields. Herein, we report a comprehensive investigation of the electrochemical anion sensing performance of novel halogen bonding (XB) and hydrogen bonding (HB) bis-ferrocene-(iodo)triazole receptors in solution and at self-assembled monolayers (SAMs), in a range of increasingly competitive aqueous organic solvent media (ACN/H2 O). In solution, the XB sensor notably outperforms the HB sensor, with substantial anion recognition induced cathodic voltammetric responses of the ferrocene/ferrocenium redox couple persisting even in highly competitive aqueous solvent media of 20 % water content. The response to halides, in particular, shows a markedly lower sensitivity to increasing water content associated with a unique halide selectivity at unprecedented levels of solvent polarity. The HB sensor, in contrast, generally displayed a preference towards oxoanions. A significant surface-enhancement effect was observed for both XB/HB receptive films in all solvent systems, whereby the HB sensor generally displayed larger responses towards oxoanions than its halogen bonding analogue.

• Authors: Sophie C Patrick, Robert Hein, Andrew Docker, Paul D Beer, Jason J Davis
• Journal: Chemistry (Weinheim an der Bergstrasse, Germany) (Chemistry) Vol. 27 Issue 39 Pg. 10201-10209 (Jul 12 2021) ISSN: 1521-3765 [Electronic] Germany
• PMID: 33881781 (Publication Type: Journal Article)
• Copyright: © 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.

Chemical References

• Anions
• Halogens
• Solvents
• Water

Topics

• Anions
• Halogens
• Hydrogen Bonding
• Solvents
• Water