Bismuth-based porous screen-printed carbon electrode with enhanced sensitivity for trace heavy metal detection by stripping voltammetry

Here we report a new disposable bismuth-coated porous screen-printed carbon electrode (Bi-P-SPCE) for trace heavy metal ions detection. The Bi-P-SPCE was fabricated by two processes: firstly, the porous screen-printed carbon electrode (P-SPCE) was prepared by combing a printing procedure of a graphite-based layer doped with CaCO3 powders with a subsequent dissolution of these powders; secondly, a Bi film layer was formed on the P-SPCE by in situ electrodepositing Bi(III) along with accumulating analytes. Due to the rough surface, large active area and low background noise of P-SPCE, the electrode exhibited significantly enhanced sensitivity for lead(II) and cadmium(II) detection compared to screen-printed carbon electrode (SPCE) and glassy carbon electrode (GCE). With a preconcentration at −1.2 V (vs. Ag/AgCl) for 300 s, the detection limits obtained on the proposed Bi-P-SPCE are 0.03 μg/L and 0.34 μg/L (S/N = 3) for lead(II) and cadmium(II), respectively. This easy-to-prepare and low-cost electrode was also successfully applied to real water sample analysis.