An aqueous ammonia sensor based on an inkjet-printed polyaniline nanoparticle-modified electrode

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Conducting polymers like polyaniline (PANI) are challenging to process in bulk form.
• Inkjet printing offers a novel fabrication method for PANI-based sensors.
• Amperometric detection of aqueous ammonia is crucial for environmental monitoring.

Purpose of the Study:

• To develop a rapid and low-cost inkjet-printed sensor for aqueous ammonia detection.
• To utilize dodecylbenzene sulfonate (DBSA)-doped polyaniline nanoparticles (nanoPANI) for sensor fabrication.
• To optimize sensor performance regarding operating pH and print layers.

Main Methods:

• Inkjet printing of DBSA-doped nanoPANI onto a screen-printed carbon paste electrode.
• Characterization of the modified electrode at varying pH and print layers.
• Amperometric detection of aqueous ammonia in a flow injection system at -0.3 V vs. Ag/AgCl.

Main Results:

• Optimal sensor performance achieved at near-neutral pH with four nanoPANI inkjet-printed layers.
• High reproducibility with below 5% RSD for ammonia injections.
• Good sensitivity with an experimental detection limit of 20 µM and theoretical limit of 3.17 µM.
• Demonstrated stability and selectivity against common interferents in refrigerant waste waters.

Conclusions:

• Inkjet printing enables rapid fabrication of processable PANI-based sensors.
• The developed sensor is ultra-low-cost, solid-state, and suitable for aqueous ammonia detection.
• This technology offers a promising solution for environmental monitoring of ammonia.