A New and All-Solid-State Potentiometric Aluminium Ion Sensor for Water Analysis

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Accurate determination of aluminium ions (Al3+) is crucial for water quality monitoring.
• Existing potentiometric methods for Al3+ determination can be complex or lack sensitivity.
• Development of robust and user-friendly sensors is needed for practical applications.

Purpose of the Study:

• To develop a novel all-solid-state potentiometric electrode system for sensitive and selective aluminium ion determination.
• To utilize a new ionophore-based aluminium ion sensor and a potassium ion pseudo-reference electrode.
• To evaluate the performance and applicability of the developed system for water analysis.

Main Methods:

• Fabrication of Ag/AgCl screen-print electrodes with a photocurable poly(n-butyl acrylate) membrane.
• Incorporation of a novel aluminium ionophore (ACH) into the working electrode membrane.
• Utilisation of a potassium ion sensor as a stable pseudo-reference electrode in a KNO3 background.
• Potentiometric measurements to determine Al3+ concentration and assess sensor characteristics.

Main Results:

• The developed sensor exhibited a linear Nernstian response for Al3+ from 10^-6 to 10^-2 M (17.70 ± 0.13 mV/decade).
• A low detection limit of 2.45 × 10^-7 M was achieved.
• The sensor demonstrated good selectivity, reversibility, repeatability, reproducibility, and stability (49-day lifetime).
• It was insensitive to pH variations between 2.0 and 8.0 with a response time under 50 s.

Conclusions:

• The novel all-solid-state potentiometric system provides a convenient and effective method for aluminium ion analysis.
• The system demonstrates comparable analytical performance to conventional methods, suitable for water treatment plant applications.
• The use of a pseudo-reference electrode simplifies the potentiometric setup for Al3+ determination.