A new potentiometric ammonium electrode for biosensor construction.

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Ammonium ion determination is crucial in various environmental and biological analyses.
• Developing selective and sensitive electrodes for ammonium detection remains an active research area.
• Existing methods may face challenges in selectivity, sensitivity, or operational range.

Purpose of the Study:

• To develop and characterize a novel ammonium-selective membrane electrode.
• To compare the performance of a palmitic acid-based PVC membrane with a carboxylated PVC membrane.
• To evaluate the potential of the developed sensor for biosensor applications.

Main Methods:

• Fabrication of poly(vinyl chloride) (PVC) membrane electrodes incorporating palmitic acid or carboxylated PVC as ion-selective components.
• Use of nonactin as an ammonium ionophore and sebacate as a plasticizer.
• Investigation of analytical parameters including pH, buffer concentration, temperature, and stirring rate.
• Determination of linear working range, sensitivity, and detection limits.

Main Results:

• The developed ammonium electrode exhibited Nernstian response (52-58 mV/p[NH4+]) over a concentration range of 10(-1) to 10(-6) M.
• A detection limit of 10(-6) M ammonium ions was achieved.
• Electrodes utilizing palmitic acid-based PVC membranes demonstrated superior performance compared to those with carboxylated PVC.
• The sensor showed stable analytical characteristics under varied experimental conditions.

Conclusions:

• The novel ammonium-selective membrane electrode based on PVC, palmitic acid, and nonactin provides effective and sensitive detection of ammonium ions.
• The palmitic acid-based sensor outperforms the carboxylated PVC-based sensor, highlighting the benefits of palmitic acid as a component.
• The developed ammonium ion sensor holds promise for integration into biosensor systems for practical applications.