A new rGO@Ni nanocomposite for simultaneous detection of Pb (II) and Cd (II)☆

Heavy metals (HMs) are recognised as major environmental pollutants due to their high toxicity, persistence, andtendency to bioaccumulate in ecosystems. Due to their high accuracy, rapid analysis, and excellent sensitivity,electrochemical detection methods have garnered considerable interest. The focus of this work is to develop asensitive, selective, and fast electrochemical sensing platform suitable for on-site monitoring of heavy metals. Bycombining the advantages of graphene oxide and metal nanoparticles, a carbon-based sensor was prepared byintegrating reduced graphene oxide with nickel nanoparticles (rGO@Ni) to enhance the detection of Pb(II) andCd(II) ions. The electrochemical performance of the CPE/rGO@Ni sensor was evaluated using cyclic voltammetry(CV) and square wave anodic stripping voltammetry (SWASV). The results demonstrate that incorporatingnickel nanoparticles into the graphene matrix significantly improves the electrochemical response toward Pb (II)and Cd (II), both in individual and simultaneous detection. The rGo@Ni nanocomposite enables the resolved andconcurrent determination of Pb (II) and Cd (II) with minimal mutual interference, highlighting its suitability formulti-ion analysis. The sensor exhibits limits of detection of 0.039 ppm for Pb (II) with a sensitivity of 533.7μAppm􀀀 1, and 0.012 ppm for Cd (II) with a sensitivity of 273.75 μAppm􀀀 1 in single ion analysis. Although thedetection limits fall within the ppm range, the ability of the rGo@Ni nanocomposite to maintain stable anddistinguished signals in the presence of coexisting ions represents a significant advantage for practical applications.These features indicate promising potential for integration into printed sensing technologies, which mayhelp mitigate the challenges associated with ppm-level detection and further improve analytical performance.