A New Type of Nitrate Potentiometric Sensor Prepared Using Hybrid Metal Oxide/Metal Nanoparticles

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Ion-selective electrodes (ISEs) are crucial for chemical analysis.
• Solid contacts in ISEs require optimization for improved performance.
• Zinc oxide (ZnO) nanoparticles offer tunable properties for electrochemical applications.

Purpose of the Study:

• To investigate noble metal-doped ZnO nanoparticles (ZnO NPs) as solid contacts in nitrate ISEs.
• To evaluate the impact of platinum (Pt), silver (Ag), and gold (Au) doping on electrode characteristics.
• To assess the suitability of these modified electrodes for real-world sample analysis.

Main Methods:

• Synthesis of noble metal-doped ZnO NPs via pulsed laser ablation in liquid.
• Fabrication of nitrate ISEs with NPs as an intermediate layer.
• Performance evaluation using potentiometry and electrochemical impedance spectroscopy (EIS).

Main Results:

• Doping ZnO NPs with noble metals significantly altered their electrical and surface properties.
• Doped NPs exhibited increased electrical capacitance and reduced contact angles.
• The electrode modified with Pt-doped ZnO NPs showed the best performance, with high capacitance and hydrophobicity.
• Successful potentiometric determination of nitrate in soil samples was achieved.

Conclusions:

• Noble metal doping is an effective strategy to enhance ZnO NP properties for solid contact applications in ISEs.
• Pt-doped ZnO NPs represent a promising material for developing high-performance nitrate sensors.
• The developed sensor demonstrates practical applicability for environmental monitoring.