Solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles as ionophore.

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Analytical Chemistry

Background:

• Ascorbic acid determination is crucial in various fields.
• Existing sensors often require complex fabrication and additives.
• Instability of formal potential is a challenge in potentiometric sensors.

Purpose of the Study:

• To develop a novel solid-contact potentiometric sensor for ascorbic acid.
• To utilize cobalt phthalocyanine nanoparticles (NanoCoPc) as a selective ionophore.
• To enhance sensor stability and performance without auxiliary materials.

Main Methods:

• Fabrication of a solid-contact electrode by drop-coating NanoCoPc on a glassy carbon electrode.
• Investigation of NanoCoPc loading and pH effects on sensor performance.
• Development of an electrochemical pretreatment method to stabilize formal potential.

Main Results:

• The sensor exhibited high selectivity for ascorbic acid over common anions.
• A wide linear response range (5.5 x 10(-7) to 5.5 x 10(-2)M) was achieved.
• Fast response (<15s), low detection limit (1.0 x 10(-7)M), and long-term stability were demonstrated.

Conclusions:

• The NanoCoPc-based sensor is a promising tool for sensitive and selective ascorbic acid detection.
• The developed electrochemical pretreatment method effectively addresses formal potential instability.
• Microsensors fabricated on different conductors proved suitable for real-world sample analysis.