Fabrication of electrochemical sensor based on the modification of graphite pencil electrode for Pb2+ and Cd2+ determination in its real samples

Pb2+ and Cd2+ are two major toxic and persistent pollutants normally generated from industry and commonly found in soil, drinking water, and aquatic environments [1,2]. So, their determinations using fast, simple, cost effective and sensitive analytical methods are in interest. This work describes the development, fabrication and optimization of s new electrochemical sensor as Metalaxyl /Cu(NP) / PGE modified electrode for simultaneous detection of Cd(II) and Pb(II) . This modified electrode has been fabricated by electrodeposition technique using Cyclic voltammetry sweeping procedure on the surface of bare graphite pencil electrode (PGE). The pencil graphite electrodes are found to be more versatile compared to other carbon based electrodes such as glassy carbon electrodes, carbon paste electrodes and diamond electrodes. This is due to the fact that the pencil graphite electrodes possess high reactivity, more sensitivity, low-cost, low background current, ease of surface modification, and easy preparation technique compared to other electrodes [3]. To detect very low levels of Cd(II) and Pb(II), square wave voltammetry technique was used owing to its high sensitivity and linearity [4,5]. Here in, to increase electrode sensitivity, the effect of some variables chemical and instrumental parameters such as pH, supporting electrolyte, and effective instrumental parameters were evaluated on the electrochemical response of the Metalaxyl /Cu(NP) / PGE modified electrode towards Cd(II) and Pb(II). Results showed that the electro-oxidation /reduction peak currents for Cd(II) and Pb(II) were obtained at the pH of 5. Other advantages of these fabricated sensor are high signal to noise ratio, low detection limit, wide dynamic concentration range and high sensitivity and selectivity. Therefore, this sensing platform is capable of simultaneously determination of Cd(II) and Pb(II) in environmental samples without any side interferences.