WITHDRAWN Flexible Screen-printed Electrochemical Sensor based on Copper Particles, Poly 1,5-Diaminonaphthalene and Carbon Black for Nitrate Detection in Water

The contamination of groundwater, rivers and lakes by nitrates has become a serious problem. The latter, mainly from agricultural activity, such as the use of chemical fertilizers, harm the aquatic ecosystem and the supply of drinking water. On the other hand, the World Health Organization (WHO) recommends a maximum level of 50 mg/L of NO3- in water, but this threshold is often exceeded, making drinking water unfit for consumption in many regions. In this context, sensitive and reliable detection methods have become a top priority. In this work, we have developed and characterized electrodes based on screen printed modified electrodes (SPEs) by a composite of a Copper film, poly 1,5-Diaminonaphthalene (1,5-DAN) and carbon black. The developed electrochemical sensor is named Cu /Poly 1,5-DAN/CB /SPE. The prepared electrode showed electroactivity towards nitrate ions in a concentration range between 1-175 µM with a detection limit less than 0,5 µM. The sensor showed very good repeatability and reproducibility and was successfully tested in different water samples.