Flexible Screen-Printed Gold Electrode Array on Polyimide/PET for Nickel(II) Electrochemistry and Sensing

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Nickel is crucial in aerospace, automotive, electronics, and fuel cells.
• Traditional nickel analysis methods (ICP-MS, AAS, ICP-AES) are costly and unsuitable for on-site testing.
• There is a need for accessible, on-site nickel detection technologies.

Purpose of the Study:

• To develop and evaluate a novel screen-printed electrode array for sensitive nickel ion (Ni²⁺) detection.
• To assess the electrochemical performance of the array using different electrolytes and nickel sources.
• To explore the potential for multiplexed analysis and applications in industrial wastewater.

Main Methods:

• Fabrication of a screen-printed electrode array with gold electrodes.
• Electrochemical analysis of Ni²⁺ using sodium sulfite (Na₂SO₃) and choline chloride-ethylene glycol (ChCl-EG) deep eutectic solvent electrolytes.
• Preparation of Ni²⁺ solutions from various nickel salts (NiCl₂·6H₂O, NiSO₄·6H₂O, NiCl₂).
• Determination of linear detection ranges and detection limits.

Main Results:

• The electrode array demonstrated electrochemical response to Ni²⁺ in both electrolytes.
• In Na₂SO₃, linear detection ranges varied based on the nickel salt used (e.g., 20-196 mM for NiCl₂·6H₂O).
• In ChCl-EG, a linear range of 0.5-10 mM (R² = 0.9995) and a detection limit of 1.6 µM were achieved.
• The array allows for nanomole-level nickel detection with small electrolyte volumes.

Conclusions:

• The novel screen-printed electrode array provides a sensitive and potentially cost-effective method for Ni²⁺ detection.
• The array's performance is influenced by electrolyte choice and the counter-ion of the nickel salt.
• The technology shows promise for on-site industrial wastewater monitoring, multiplexed toxic metal analysis, and applications in medical diagnostics and food safety.