Strontium(II) sensor based on a modified calix[6]arene in PVC matrix

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Materials Science

Background:

• Ion-selective electrodes (ISEs) are crucial for detecting specific ions in various matrices.
• Calixarene derivatives have shown promise as ionophores in ISE development.
• Strontium ion (Sr2+) analysis is important in environmental and biomedical fields.

Purpose of the Study:

• To evaluate 5,11,17,23,29,35-Hexakis(1,1,3,3-tetramethylbutyl)-37,38,39,40,41,42-hexakis(carboxy methoxy)calix[6]arene (I) as an ionophore for Sr2+ detection.
• To optimize the performance of a Sr2+-selective electrode by investigating plasticizers and anion excluders.
• To assess the electrode's response characteristics, selectivity, and operational stability.

Main Methods:

• Fabrication of a potentiometric sensor using a membrane incorporating calixarene (I), PVC, DBA plasticizer, and NaTPB anion excluder.
• Electrochemical characterization including Nernstian response evaluation, pH influence study, and selectivity assessment against other alkaline earth metal ions.
• Testing the sensor's performance in potentiometric titrations.

Main Results:

• The optimized electrode exhibited a Nernstian response for Sr2+ over a wide concentration range (1.9 x 10(-5) to 1.0 x 10(-1) M).
• The electrode demonstrated good potential stability and an operational lifetime of 4 months.
• High selectivity for Sr2+ over other alkaline earth metal ions was confirmed by K(A,B)(Pot) values.
• The sensor successfully functioned as an indicator electrode in potentiometric titrations.

Conclusions:

• The developed calixarene-based ionophore is effective for the selective and sensitive detection of Sr2+.
• The optimized potentiometric sensor offers a robust and stable analytical tool for Sr2+ determination.
• The sensor's applicability extends to direct potentiometric titrations, highlighting its versatility.