# Enhancing Analytical Performance of Ammonium Potentiometric Sensors with Carbon Nanocomposites

## TL;DR

This paper introduces a new ammonium sensor using carbon nanocomposites that improves accuracy and durability for environmental monitoring.

## Contribution

A novel carbon nanocomposite-based sensor with enhanced analytical performance and stability for ammonium detection.

## Key findings

- Modified electrodes showed an ideal theoretical slope of 58.4 mV·dec−1.
- Potential drift was reduced by nearly 50 times compared to unmodified electrodes.
- The sensor is resistant to environmental factors like light, O2, and CO2.

## Abstract

The use of carbon nanocomposites significantly improves the performance of sensors.

A simple and cheap all-solid-state ammonium potentiometric sensor was developed.

The developed sensor is resistant to changes in measurement conditions.

It is suitable for monitoring ammonium in environmental samples.

This paper presents a new type of ammonium electrode that shows a significant improvement in analytical performance compared to unmodified electrodes. The aim of the study was to develop electrodes with better electrochemical parameters, achieved by applying a modification in the form of a solid contact layer based on a carbon nanocomposite consisting of carbon nanofibers and multi-walled carbon nanotubes. Measurements were made to evaluate the basic analytical parameters of both unmodified electrodes and those enriched with an intermediate layer in the form of a carbon nanocomposite. The composite-modified electrodes showed an almost ideal theoretical slope value (58.4 mV·dec−1), a lower detection limit, and linearity that remained constant over time. Stability tests showed that electrodes with nanocomposites achieved a potential drift that was almost 50 times lower. An improvement in potential reversibility was also achieved. Another important advantage of the modified electrodes is their resistance to external conditions such as light and the presence of O2 and CO2. In addition, they exhibit selectivity typical for ammonium electrodes. Based on the results obtained, it was found that the multiwalled carbon nanotubes and carbon nanofibers nanocomposite effectively acts as a solid contact layer, which may form the basis for the development of modern, durable, and precise sensors for the determination of ammonium ions in various environments. The determination of NH4+ ions in soil was conducted with success.