A New Azo-Schiff Base Dual-mode Chemosensor: Colorimetric Detection of Cobalt Ions and Fluorometric Detection of Aluminum Ions in Aqueous Ethanol Solution

Abstract

A new chemosensor H 2 L has been designed and synthesized based on an Azo-Schiff base ligand for the selective and sensitive sensing of Co 2+ and Al 3+ ions. The H 2 L as uorescence chemosensor exhibits a linear response toward Al 3+ ions in the concentration range of 1.91 × 10 − 8 M to 4.8 × 10 − 6 M with a limit of detection of 1.91 × 10 − 8 M. The chemosensor also displayed high colorimetric sensitivity for Co 2+ .Fluorescence switch based on the control of EDTA and Al 3+ proved H 2 L could act as a reversible chemosensor. The molecular structure of [NiL] complex has been determined by X-ray crystallography. Author DeclarationsAuthor Contributions Azadbakht and Mostafa Koolivand performed collection of absorption/emission spectra, data analysis, and writing original draft. Naemeh Chidan developed the methodology for synthesis. Saeid Menati synthesized the compounds.

Azobenzene-Containing Schiff-Bases—Syntheses and Dyes Applications

“…Indeed, when two cations can selectively be detected by two different optical methods, this dual mode is of great interest. This is the case for example for the dual mode H 2 L ligand (S5, Figure 2) which showed a selective fluorescence recognition of Al 3+ with a noticeable fluorescence enhancement and a colorimetric detection of Co 2+ [81]. [75]; Schiff base-linked arylazopyrazoles Ln S2 [66]; receptors Rn S3 [77]; bis(azo) ligand S4 [78]; dual mode H2L S5 [81].…”

“…Rhodamine can also be part of a tripodal probe (S7, Figure 3) [83] which can recognize or discriminate F − , AcO − and H2PO4 − anions over a wide range of pH (3 to 12). [75]; Schiff base-linked arylazopyrazoles Ln S2 [66]; receptors Rn S3 [77]; bis(azo) ligand S4 [78]; dual mode H 2 L S5 [81].…”

“…Figure 2. Structures of ligands H 2 L n S1[75]; Schiff base-linked arylazopyrazoles Ln S2[66]; receptors Rn S3[77]; bis(azo) ligand S4[78]; dual mode H 2 L S5[81].…”

Magnetic Hydrogel Beads as a Reusable Adsorbent for Highly Efficient and Rapid Removal of Aluminum: Characterization, Response Surface Methodology Optimization, and Evaluation of Isotherms, Kinetics, and Thermodynamic Studies

“…In this regard, the World Health Organization standard for the maximum permissible level of aluminum in drinking water is 200 μg/L . Different spectroscopic and electrochemical methods have been widely used for aluminum detection. − Prior to the detection of trace levels of metal ions, the usage of adsorbents can eliminate or minimize the sample matrix effects and improve the sensitivity of the method . Various types of adsorbents have been used for the removal and detection of metal ions in environmental, biological, and food samples. , Especially in the past decade, adsorbents derived from natural materials such as chitosan, cellulose, carrageenan, and alginate have been widely used for the removal of diverse metal ions. − Different types of self-assembled gel structures have also been employed in several fields, such as biomedical research, tissue engineering, and drug delivery systems for removal of contaminants. − …”