Prussian Blue Analogue of Copper-Cobalt Decorated with Multi-Walled Carbon Nanotubes Based Electrochemical Sensor for Sensitive Determination of Nitrite in Food Samples
Abstract Cu-Co Prussian Blue analogue (CuII3[CoIII(CN)6]2)/multi-walled carbon nanotubes (Cu-Co PBA/MWCNTs) composite was synthesized for fabrication of an electrochemical sensor for detection of nitrite. The morphology and composition of the fabricated nanomaterial were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behavior and mechanism of the fabricated biosensor. Experimental results showed that Cu-Co PBA/MWCNTs/GCE had excellent electrochemical activity towards nitrite, which was superior to that of Cu-Co PBA and MWCNTs. Under the optimal conditions, a wide linear range from 10–400 μM and 400–2100 μM and a detection limit of 0.5 μM were obtained. Moreover, this sensor was employed to determine the concentration of nitrite in ham sausage and mustard samples, and showed excellent selectivity, good anti-interference, repeatability and satisfied recovery.