Nitrate amperometric sensor in neutral pH based on Pd nanoparticles on epoxy-copper electrodes

Amperometric nitrate sensing at neutral pH using an epoxy-copper electrode modified with palladium nanoparticles is presented. After epoxy-copper is hardened and polished, electroless deposition is employed for the deposition of Pd nanoparticles. Scanning electron microscopy and energy-dispersive X-ray spectroscopy reveal the morphology and composition of the Cu/Pd surface. The effect of Pd deposition time toward nitrate electroreduction is investigated, highlighting the importance of the bimetallic catalyst. The optimized electrode shows a linear response at pH = 7 in the range from 2 to 35 ppm of nitrate. The simplicity and cost effectiveness of the fabrication process makes this Cu/Pd electrode a good candidate for distributed nitrate monitoring and determination in the field.