Enhanced Magnesium Ion Sensing Using Polyurethane Membranes Modified with ĸ-Carrageenan and D2EHPA: A Potentiometric...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Accurate detection of magnesium (Mg²⁺) ions is challenging due to low concentrations and interference from similar ions.
• Sensitive and selective analytical methods are crucial for various applications, including biological and environmental monitoring.

Purpose of the Study:

• To develop a novel potentiometric ion-selective electrode (ISE) for sensitive and selective detection of Mg²⁺ ions.
• To characterize the performance of the ISE, including its response, detection limit, selectivity, and stability.

Main Methods:

• Fabrication of a modified polyurethane membrane incorporating κ-carrageenan and D2EHPA.
• Potentiometric measurements to evaluate the ISE's performance across a range of Mg²⁺ concentrations.
• Selectivity testing against interfering ions (K⁺, Na⁺, Ca²⁺).
• Physicochemical characterization using water contact angle, FTIR, XRD, and SEM.

Main Results:

• The ISE demonstrated a near-Nernstian response (29.49 mV/decade) within the 10^-9-10^-4 M range.
• Achieved a low detection limit of 1.25 × 10^-10 M and a response time of 200 s.
• Exhibited excellent selectivity over common interfering ions and stability over a pH range of 6-8 for one month.

Conclusions:

• The developed potentiometric ISE offers a promising tool for sensitive and selective Mg²⁺ detection.
• Membrane modification enhanced hydrophilicity and ion diffusion, contributing to improved sensor performance.
• The sensor's reliability and stability make it suitable for practical analytical applications.