Impedance Sensor for Real-Time Ammonium Detection Based on MWCNT/ZnO Nanocomposites

IEEE Trans Nanobioscience. 2023 Jan;22(1):121-127. doi: 10.1109/TNB.2022.3166388. Epub 2022 Dec 29.

Abstract

This work reports on the development of an impedance sensor-based real-time-field specific system to monitor aqueous Ammonium (NH4+). The sensing element was fabricated by modifying screen-printed interdigitated electrodes (IDEs) with a hybrid nanocomposite of Multi-Wall Carbon Nanotube (MWCNT) with Zinc Oxide (ZnO) nanocrystals. The NH4+ of the water was monitored, and it exhibited a sensitivity of 67.13 Ω /mM with average correlation coefficients of 0.80. The impedance magnitude ( Ω ) of the NH4+ sensor was unaffected by the presence of Fe2+, Ni2+, K+ and P+ interfering cations. The developed sensor was interfaced with an IoT-enabled NodeMCU microcontroller, enabling a direct method for continuous monitoring of NH4+ concentrations. This integrated system is interconnected to the field-deployed sensor nodes, which provide real-time NH4+ levels to the remote user through web applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Compounds*
  • Electric Impedance
  • Electrochemical Techniques
  • Electrodes
  • Nanocomposites* / chemistry
  • Nanotubes, Carbon* / chemistry
  • Zinc Oxide* / chemistry

Substances

  • Zinc Oxide
  • Nanotubes, Carbon
  • Ammonium Compounds