A novel synthesized SDAB/MWCNTs sensor to investigate Cd(ii) in Oryza sativa L., egg yolk and Camellia sinensis of real samples using SWASV technique

The present research aims to create a mercury-free electrode employing MWCNTs (nanotubes)/SDAB ligand for the measurement of Cd(II) via stripping voltammetry. SEM with EDX spectra showed that the morphology of the modified SDAB/MWCNTs/PGE electrode surface exhibited a grass cloud-shaped like-crystal structure, while the preconcentrated Cd(II)-SDAB/MWCNTs/PGE surface exhibited a square cube-like crystal structure. As determined by electrochemical impedance spectroscopy, the conductance (σ) values for the MWCNTs/PGE and SDAB/MWCNTs/PGE-modified electrodes were 225 × 10⁻⁵ S cm⁻¹ and 393.5 × 10⁻⁵ S cm⁻¹, respectively. As a result, an electrochemical sensor with superior repeatability, stability, and anti-interference capabilities for Cd(II) was developed. The stripping analysis of Cd(II) was investigated using SWASV and CV methods. Using SWASV, the linear range of the Cd(II) response was determined to be between 2.3 and 120.4 μg L⁻¹, with a limit of detection of 0.7 μg L⁻¹. Finally, the recovered values of Cd(II) in freshly prepared Oryza sativa L., egg yolk, and Camellia sinensis samples by SWASV were compared to the data obtained from atomic absorption spectroscopy (AAS).