A New Cr3+ Electrochemical Sensor Based on ATNA/Nafion/Glassy Carbon Electrode.

Reda M El-Shishtawy,Abdullah M Asiri,Mohammed M Rahman,Muhammad Nadeem Arshad,Tahir Ali Sheikh,Fatimah A M Al-Zahrani

doi:10.3390/ma13122695

Reda M El-Shishtawy, Abdullah M Asiri + Show 4 more

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https://doi.org/10.3390/ma13122695

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Abstract

A new electrochemical sensor of metal cation in an aqueous solution based on homobifunctional tridentate disulfide Schiff base and named 1,1′-(-((disulfanediylbis(2,1-phenylene))bis(azaneylylidene))bis(methaneylylidene))bis(naphthalene-2-ol) (ATNA) was easily obtained quantitatively from the condensation reaction of 2-hydroxy-1-naphthaldehyde and 2-aminothiophenol, and then fully characterized by spectroscopic techniques for structure elucidation. The molecular structure of ATNA was also confirmed by a single-crystal X-ray diffraction study to reveal a new conformation in which the molecule was stabilized by the O–H…N type intramolecular hydrogen bonding interactions in both moieties. The ATNA was used as a selective electrochemical sensor for the detection of chromium ion (Cr3+). A thin film of ATNA was coated on to the flat surface of glassy carbon electrode (GCE) followed by 5 % ethanolic Nafion in order to make the modified GCE (ATNA/Nafion/GCE) as an efficient and sensitive electrochemical sensor. It was found to be very effective and selective against Cr3+ cations in the company of other intrusive heavy metal cations such as Al3+, Ce3+, Co2+, Cu2+, Ga3+, Hg2+, Mn2+, Pb2+, and Y3+. The detection limit at 3 S/N was found to be 0.013 nM for Cr3+ ions within the linear dynamic range (LDR) (0.1 nM–10.0 mM) of Cr3+ ions with r2 = 0.9579. Moreover; this work instigates a new methodology for developing the sensitive as well as selective electrochemical toxic cationic sensors in the field of environmental and health care.

Highlights

The chemical factories and mining facilities throughout the world discharge overwhelming metal particles and severely affect the environment [1,2,3,4]
It was envisioned that having disulfide-containing homobifunctional Schiff base as a tridentate ligand would make a stable film on a glassy carbon electrode for the electrochemical detection of toxic metal ions from aqueous solution
It is suggested that the formation of the ATNA ligand proceeds via condensation to get the corresponding Schiff base, which further undergoes the in situ oxidation of thiol to the corresponding disulfide by virtue of the dissolved oxygen

Summary

Introduction

The chemical factories and mining facilities throughout the world discharge overwhelming metal particles and severely affect the environment [1,2,3,4]. Accurate quantitative and qualitative detection of such heavy metal ions in an aqueous solution is of prime importance for the protection of the environment In this regard, the Schiff base structure represents an extraordinary class of ligands because of their facile synthesis from diverse reagents, and the formation of a wide range of complexes with potential applications in different fields such as dye affinity chromatography [5], liquid crystals [6,7], nanocomposite-based polyazommethine [8], medicine [9,10], corrosion inhibitors [11], catalysis [12]. The present work was made to explore the possibility of synthesizing and using of homobifunctional tridentate disulfide Schiff base derived from 2-hydroxy-1-naphthaldehyde and 2-aminothiopheno as a selective cation sensor by an electrochemical approach.

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