فهرست نشریات علمی دسترسی آزاد ایران

An electrochemical sensor has been developed for detecting Pb2+ in water. The sensor is made from screen printed carbon electrode (SPCE) modified by MWCNT@SiO2-APTES (Pb2+). The synthesis of MWCNT@SiO2 involves adding MWCNT to TEOS, and APTES (Pb2+) is a complex compound of APTES (3-Aminopropyltriethoxysilane) with Pb2+ in ethanol. MWCNT@SiO2 and APTES (Pb2+) were combined at 50 oC for 24 h. To remove excess APTES, it was washed with ethanol, and Pb2+ was removed by acetic acid, thereby forming a Pb2+ template. Characterization of MWCNT@SiO2-APTES (Pb2+) based on the FTIR spectrum, XRD, and surface morphology by scanning electron microscopy (SEM). Electrochemical characterization of electrodes by a standard solution of Fe(CN)63- 5 mM in 0.1 M KCl and 10 ppm Pb2+ in 0.1 M acetic buffer, pH 6 solution. Determination of Pb2+ levels in water was achieved by square wave voltammetry (SWV). The results showed that MWCNT@SiO2-APTES (Pb2+) had been formed and electrochemically fulfilled the requirements as a sensor material. The diffusion coefficient of Fe(CN)63- in MWCNT@SiO2-APTES (Pb2+) is lower than in unmodified SPCE, and the opposite is true for Pb2+ solution. Analytically, this method has a limit of detection (LoD) (S/N=3) of 0.08 ppm linear concentration range of 0.1-10 ppm, and a sensitivity of 13.5 µA/ppm, enabling it to be applied to water samples containing  Pb2+ concentrations < 0.1 ppm.