Towards green synthesis of monodisperse Cu nanoparticles: An efficient and high sensitive electrochemical nitrite sensor

The development of highly stable and biocompatible Cu nanocomposite has been employed herein as an electrocatalytic active material for electrochemical sensing. The synthesis of carboxymethyl cellulose (CMC) stabilized Cu nanoparticles in aqueous medium under room temperature has been carried out. To identify the surface properties of the synthesized Cu nanoparticles, X-ray diffraction (XRD) and X-ray photoelectron spectroscopic (XPS) studies have been carried out. The as-prepared Cu nanoparticles were dispersed with multi-walled carbon nanotubes (MWCNTs) and the resultant dispersion has been deposited over glassy carbon (GC) electrode to obtain Cu/MWCNTs/GC modified electrode. The Cu/MWCNTs modified GC electrode exhibits a well-defined oxidation peak at Epa = 0.93 V (vs. SCE) towards the oxidation of nitrite. Amperometric investigations of the modified electrode revealed a wide linear range for nitrite from 5 μM to 1260 μM with a sensitivity and detection limit of 455.84 μA mM⁻¹ cm⁻² and 1.8 μM, respectively. The proposed modified electrode displayed excellent selectivity and reproducibility and has been successfully utilized for determination of nitrite in real samples.