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Preparation of Binary and Ternary Deep Eutectic Systems
Published on: October 31, 2019
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Binary and Ternary Deep Eutectic Solvents for Methylene Green Electropolymerization on Multiwalled Carbon Nanotubes:
Joseany M S Almeida1, Zeferino S B Pedro1, Rafael M Buoro2
1Department of Chemistry, CEMMPRE, ARISE, Faculty of Sciences and Technology, University of Coimbra, 3004-535, Coimbra, Portugal.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|June 20, 2024
Summary
Deep eutectic solvents based on choline chloride were used to electropolymerize methylene green. The best performing solvent enabled a sensor for simultaneous determination of 5-aminosalicylic acid and acetaminophen in pharmaceuticals.
Area of Science:
- Electrochemistry
- Materials Science
Background:
- Deep eutectic solvents (DES) offer tunable properties for electrochemical applications.
- Choline chloride (ChCl) is a common component in DES, with oxalic acid (OA) and ethylene glycol (EG) as potential hydrogen bond donors.
Purpose of the Study:
- To evaluate ChCl-based binary and ternary DES for methylene green electropolymerization.
- To develop a sensor for the simultaneous determination of 5-aminosalicylic acid (5-ASA) and acetaminophen (APAP).
Main Methods:
- Electropolymerization of methylene green using various ChCl-based DES (ChCl:OA, ChCl:EG, and ternary DES).
- Optimization of DES composition, including molar ratios and water content.
- Characterization of polymer growth, viscosity, and ionic conductivity.
- Fabrication of a sensor using poly(methylene green)/multi-walled carbon nanotube/glassy carbon electrode (PMG/MWCNT/GCE) in tDES.
- Simultaneous determination of 5-ASA and APAP using differential pulse voltammetry.
Main Results:
- The highest polymer growth was achieved in a ternary DES (ChCl:OA:EG) with 13% added water.
- This optimal tDES exhibited lower viscosity and higher ionic conductivity, facilitating enhanced cation radical formation and polymer growth.
- The developed sensor demonstrated effective simultaneous determination of 5-ASA and APAP within the concentration range of 1–200 μM.
- Achieved detection limits were 0.37 μM for 5-ASA and 0.49 μM for APAP.
- The sensor showed good repeatability, reproducibility, and stability, and was successfully applied to pharmaceutical formulations.
Conclusions:
- Choline chloride-based ternary deep eutectic solvents are effective media for methylene green electropolymerization.
- The optimized tDES-based sensor provides a sensitive and selective method for the simultaneous quantification of 5-ASA and APAP.
- This approach holds promise for applications in pharmaceutical analysis.
Keywords:
5-aminosalicylic acid and acetaminophenbinary and ternary deep eutectic solventselectropolymerizationmethylene greenmultiwalled carbon nanotubes
