Highly sensitive and disposable voltammetric nano-sensor for analysis of Sudan I based on CuCo₂O₄ nanorods

In this research, CuCo₂O₄ nanorods (CuCo₂O₄ NRs) were prepared using a simple hydrothermal technique and characterized by using various techniques. Subsequently, a highly sensitive and simple electrochemical sensor was prepared by modifying a screen-printed graphite electrode with CuCo₂O₄ NRs (CuCo₂O₄ NRs/SPGE) and applied for the detection of sudan I. The electrocatalytic oxidation of sudan I was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), chronoamperometry, and linear sweep voltammetry (LSV). The modification of the electrode surface with CuCo₂O₄ NRs exhibited the highest electro-catalytic activity towards sudan I oxidation, resulting in an improved sensitivity compared to the unmodified electrode. Based on these findings, we analyzed a screen-printed sensor (CuCo₂O₄ NRs/SPGE) using DPV for sudan I determination. The sensor demonstrated a linear response ranging from 0.04 µM to 560.0 µM, with a limit of detection (LOD) of 0.01 µM and a sensitivity of 0.097 µM/µA. The suitability of the proposed sensor for sudan I determination in real samples was also demonstrated, with good recovery results ranging from 97.6 to 104.0% and a maximum relative standard deviation (RSD) of 3.5%.