Affiliation:
1. Department of Natural Sciences The Open University of Israel 1 University Road Ra'anana 4353701 Israel
2. Hybrid Materials for Opto-Electronics Group MESA+ Institute Faculty of Science and Technology University of Twente Drienerlolaan 5 7522 NB Enschede The Netherlands
3. Faculty of Chemistry Technion-Israel Institute of Technology Technion Haifa Israel
4. Molecular Nanofabrication Group MESA+ Institute Faculty of Science and Technology University of Twente Drienerlolaan 5 7522 NB Enschede The Netherlands
Abstract
AbstractIn the last two decades, perchlorate salts have been identified as environmental pollutants and recognized as potential substances affecting human health. We describe self‐assembled monolayers (SAMs) of novel semiaza‐bambus[6]urils (semiaza‐BUs) equipped with thioethers or disulfide (dithiolane) functionalities as surface‐anchoring groups on gold electrodes. Cyclic voltammetry (CV) with Fe(CN)63−/4− as a redox probe, together with X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and ellipsometry, were employed to characterize the interactions at the interface between the anchoring groups and the metal substrate. Data showed that the anion receptors′ packing on the gold strongly depends on the anchoring group. As a result, SAMs of BUs with lipoic amide side chains show a concentration‐dependent layer thickness. The BU SAMs are extremely stable on repeated electrochemical potential scans and can selectively recognize perchlorate anions. Our electrochemical impedance spectroscopy (EIS) studies indicated that semiaza‐BU equipped with the lipoic amide side chains binds perchlorate (2–100 mM) preferentially over other anions such as F−, Cl−, I−, AcO−, H2PO4−, HPO42−, SO42−, NO2−, NO3−, or CO32−. The resistance performance is 10 to 100 times more efficient than SAMs containing all other tested anions.
Funder
Israel Science Foundation
Subject
General Chemistry,Catalysis,Organic Chemistry