Novel nitrogen-rich anchored nickel (II) phthalocyanine with composite of multiwalled carbon nanotubes on modified glassy carbon electrode: Sensitive and selective electrocatalytic activity of nitrite

This work describes the synthesis of novel nickel tetra substituted 6-bromobenzothiazole carboxamide nickel (II) phthalocyanine (NiTBBTCAPc) and confirmed by spectroscopic-microscopic methods and as well as electrochemical analysis. The electrochemical oxidation of nitrite was studied on NiTBBTCAPc-multiwalled carbon nanotube (MWCNTs)/glassy carbon electrode (GCE) due to its better electron transferring ability than bare GCE and NiTBBTCAPc/GCE. As there is acceleration in surface area of GCE by multiwalled carbon nanotubes, a cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometric techniques utilized for nitrite sensor were developed. The sensor exhibited a fast response towards nitrite with a detection limit of 3.012 nM and a linear concentration range of 50-900 nM by the CV method. The fabricated sensor shows excellent electrocatalytic activity compared with the modified electrode with Pc with a composite of MWCNTs towards oxidation of nitrite. The NiTBBTCAPc-MWCNTs/GCE shows good repeatability, stability, and high selectivity even in the presence of excess ascorbic acid (AA), dopamine (DA), uric acid (UA), paracetamol (PA), glucose, Pb (II), Cd (II), Ca (II), and Mg (II). Finally, for usage in practical applications, the modified electrode was employed to achieve quantitative detection of nitrite in drinking water and cabbage vegetable samples, respectively.

Automated summary

This work synthesized a novel nickel phthalocyanine compound and confirmed its structure using spectroscopic-microscopic methods and electrochemical analysis. The synthesized NiTBBTCAPc-MWCNTs showed enhanced electron transferring ability and electrocatalytic activity compared to bare GCE and other composite materials. The sensor exhibited fast response, good stability, and high selectivity towards nitrite. The modified electrode was successfully applied for quantitative detection of nitrite in drinking water and cabbage vegetable samples.