Rapid electrochemical nitrate sensing using flexible screen-printed electrodes modified with carbon black/poly (1,5-diaminonaphthalene)/copper dendrite hybrid interfaces

The rising demand for sensitive and accurate nitrate ion detection in water has motivated the design of novel electroactive sensing materials. Conducting polymers, notably, provide a highly adaptable surface for engineering materials with superior electrochemical performance. In this study, a composite electrode for nitrate detection was fabricated by polymerizing a 1,5-diaminonaphthalene (poly 1,5-DAN) layer on a carbon black modified screen-printed electrode (CB/SPE), followed by the electrodeposition of copper particles through cyclic voltammetry. The resulting electrodes were characterized by scanning electron microscopy (SEM) to examine surface morphology revealing a dendritic form of Cu (Cu Ds) and by X-ray photoelectron spectroscopy (XPS) to determine their chemical composition. Electrochemical techniques were employed throughout the study to investigate the electrode behavior and evaluate the nitrate sensing performance. The Cu Ds/poly 1,5-DAN/CB/SPE electrode showed strong performance for nitrate sensing, offering a broad linear detection range from 1 to 175 µM and a low detection limit of 0.28 µM. In addition, the sensor maintained good stability throughout its measurements and a high reproducibility, confirming its robustness for reliable analytical use. Notably, the simple deposition method used to assemble the polymer, carbon black and copper particles produces a functional composite material with potential applications not only in nitrate sensing but also in water quality monitoring and denitrification.