All-solid-state polymeric membrane ion-selective miniaturized electrodes based on a nanoporous gold film as solid...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Ion-selective electrodes (ISEs) are crucial for ion concentration measurements.
• Traditional solid contacts in ISEs can suffer from instability and water layer formation.
• Developing robust and reliable solid contacts is essential for advanced ISE applications.

Purpose of the Study:

• To develop a novel all-solid-state polymeric membrane ion-selective electrode (ISE) using a nanoporous gold (NPG) film as a solid contact.
• To evaluate the performance and stability of the NPG-based ISE compared to conventional designs.
• To demonstrate a versatile method for fabricating miniaturized, low-maintenance ISEs.

Main Methods:

• In situ formation of a nanoporous gold (NPG) film on a gold wire electrode via electrochemical alloying/dealloying.
• Characterization of NPG film properties using cyclic voltammetry and electrochemical impedance spectroscopy.
• Fabrication and testing of an all-solid-state potassium (K(+)) ISE incorporating the NPG film.

Main Results:

• The NPG film exhibited excellent conductivity, high surface area, and high double-layer capacitance.
• The NPG-based K(+) ISE demonstrated a stable Nernstian response from 10(-6) to 10(-2) M with a detection limit of 4.0 × 10(-7) M.
• The proposed electrode showed improved potential stability and reduced water layer formation compared to coated-wire ISEs, with a reusable solid contact.

Conclusions:

• The in situ formed NPG film provides a well-defined, stable interface for all-solid-state ISEs.
• The NPG-based ISE offers enhanced performance, stability, and reusability, making it suitable for miniaturized sensor applications.
• This method presents a versatile approach for fabricating robust and reliable ISEs with reduced maintenance requirements.