Sensitive sensors for amperometric detection of nitrite based on carbon-supported PdNi and PdCo bimetallic nanoparticles

Abstract

Carbon-supported PdNi (PdNi/C) and PdCo (PdCo/C) nanoparticles (NPs) were synthesized and modified on a glassy carbon electrode (GCE) to fabricate highly sensitive amperometric nitrite sensors. Cyclic voltammetry (CV) and an amperometric i–t curve were used to characterize the electrochemical behavior of the electrodes in the presence of nitrite. From the results, both the PdNi/C- and PdCo/C NPs-modified electrodes exhibited better electrochemical properties than the commercial Pd/C catalyst with equal metal content (10%). Moreover, both the PdNi and PdCo sensors exhibited remarkable sensitivity of 5.23 and 5.52 mA mM⁻¹ cm⁻², respectively. Interference studies showed that the modified electrodes exhibited excellent selectivity toward nitrite. In addition, the proposed sensors were applied to determine the nitrite content in several foods and moat water with satisfactory results.