Improved potentiometric response of solid-contact lanthanum (III) selective electrode

Area of Science:

• Electroanalytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Solid-contact ion-selective electrodes (SC-ISEs) are crucial for ion detection.
• Developing stable and sensitive ion-selective electrodes remains a challenge.
• Lanthanum (III) detection is important in various scientific fields.

Purpose of the Study:

• To report the first analytical application of magnetic graphene hybrids and 2,2-dithiodipyridine in a lanthanum (III) SC-ISE.
• To enhance the stability and performance of lanthanum (III) SC-ISEs.
• To improve the detection limit for real-time lanthanum (III) monitoring.

Main Methods:

• Fabrication of magnetic graphene hybrids using covalent bonding of Fe3O4 nanoparticles (NPs) to graphene oxide (GO).
• Integration of the magnetic graphene hybrid with 2,2-dithiodipyridine as the ionophore-transducer material.
• Electrochemical characterization of the developed solid-contact lanthanum (III) selective electrode.

Main Results:

• The electrode demonstrated a near-Nernstian response to lanthanum (III) over a wide concentration range (1.0×10⁻⁹ to 1.0×10⁻³ M) with a slope of 17.81 mV/dec.
• Achieved a significantly improved detection limit of 2.75×10⁻¹⁰ M for lanthanum (III).
• Exhibited excellent selectivity, a broad applicable pH range (3.0–8.0), fast response time (10s), and long operational life (2 months).

Conclusions:

• The developed lanthanum (III) SC-ISE based on magnetic graphene hybrids and DTDP offers superior performance.
• The covalent bonding strategy effectively prevents leaching of Fe3O4 NPs, enhancing electrode stability.
• This advancement paves the way for real-time lanthanum (III) detection using ion-selective electrodes.