Simultaneous quantification of Cd(II) and Pb(II) by bismuth/poly(bromocresol purple) modified screen-printed carbon-electrode in wastewater

Abstract

There are traces of lead and cadmium in many sample matrices, which can be harmful to human health, even in small amounts. To protect human health, it is imperative to identify the presence of Pb(II) and Cd(II) in the water. This paper describes the fabrication of a simple, sensitive, and selective bismuth-coated poly(bromocresol purple) modified screen-printed carbon electrode, denoted as Bi/poly(BCP)/SPCE, for the rapid or simultaneous electrochemical detection of Cd(II) and Pb(II) in wastewater samples. The bismuth film was simultaneously deposited with the target metals via differential pulse anodic stripping voltammetry (DPASV), whereas the electropolymerization of poly(BCP) was performed by cyclic sweeping. Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS) were used to characterize the developed electrodes. Under optimum conditions, a wide linear range of 0−250 μgL-1 with a potentially lower limit of detection (LOD) of 0.360 μgL-1 for Cd(II) and 0.270 μgL-1 for Pb(II) was achieved. The developed electrode also demonstrated significantly better repeatability, reproducibility, and stability for the simultaneous detection of Cd(II) and Pb(II) in real wastewater samples, with no significant potential interfering ions and recovery rates of 94–107%. Moreover, the developed electrode having the advantage of allowing simultaneous detection could also take part in advancing the search for the replacement of the conventional mercury film electrodes which are not ecologically friendly.