Highly sensitive and selective detection of nitrite by polyaniline linked tetra amino cobalt (II) phthalocyanine surface functionalized ZnO hybrid electrocatalyst

The highly sensitive nanoscale detection of nitrite is one of the major concerns in recent research due to its serious hazardous effects on the environment. The state-of-the-art fabrication of a cost-effective electrochemical nitrite sensor is one of the impetuses of modern research. A polyaniline-linked tetra amino cobalt phthalocyanine surface functionalized ZnO hybrid nanomaterial (PA-TaCoPc@ZnO) for sensitive electrochemical detection of nitrites is presented. Surface functionalization of ZnO nanoparticles with tetra amino cobalt (II) phthalocyanine (TaCoPc) yields TaCoPc-functionalized ZnO nanoparticles (TaCoPc@ZnO) in the first step, followed by the introduction of polyaniline (PANI) via oxidative polymerization in the presence of aniline to yield PA-TaCoPc@ZnO. The fabrication of the sensor was carried out by modifying the glassy carbon electrode with ZnO, TaCoPc@ZnO, tetra amino-substituted phthalocyanine linked by polyaniline (PA-TaCoPc), and PA-TaCoPc@ZnO to evaluate the electrochemical performance. Sensors of PA-TaCoPc@ZnO exhibited superior electrocatalytic activity, selectivity, sensitivity, and a low limit of detection (nanomolar concentration) toward nitrite ions compared to other systems. The remarkable electrocatalytic performance of PA-TaCoPc@ZnO can be attributed to the synergetic effect of the high surface area of nanosized ZnO with conducting polyaniline and metal-centered supramolecular TaCoPc.