A novel sensitive electrode based on a chitosan/rGO/CuO composite for the detection of urea concentration

Chitosan/reduced graphene oxide/copper oxide (CS/rGO/CuO) films were successfully deposited on a screen-printed electrode (SPE) surface by applying the electrodeposition technique and were utilized in detecting urea concentration using cyclic voltammetry (CV). The current study presents a novel sensitive electrode based on CS/rGO/CuO used to detect urea fertilizer. The characterization of the prepared samples was conducted using FTIR, XRD, and cyclic voltammetry. FTIR and XRD analyses confirmed that rGO and CuO were successfully dispersed in the CS matrix. The FE-SEM morphology showed a slight agglomeration, which was caused by physical interaction among CS, rGO and CuO. The CS/rGO/CuO-modified SPE had an increased electrochemical performance compared with the CS-modified SPE. Our reported study revealed that the CS/rGO/CuO 0.8%-modified SPE has extremely promising electrochemical performance. The sensing properties of CS/rGO/CuO in various concentrations of urea were studied using CV. In this study, the obtained sensitivity and <i>R</i>-square (<i>R</i> ²) values were 1.93 × 10^-3 μA μM^-1 cm^-2 and 0.9599, respectively. In addition, the observed electrocatalytic current had a limit of detection of 0.14 μM and a limit of quantification of 0.49 μM. These results indicate that the CS/rGO/CuO-modified SPE can be used to detect urea concentration, in which the addition of CuO concentration contributes significantly to the sensing properties of the resulting modified electrodes.