Enhanced voltammetric determination of metal ions by using a bismuthene-modified screen-printed electrode

A new bismuthene carbon-based screen-printed electrode (2D Bi-exf-SPCE) was easily prepared, taking advantage of the strongest features of exfoliated layered bismuth (bismuthene) for metal ions detection by differential pulse anodic stripping voltammetry (DPASV). An exfoliated bismuth suspension was drop-casted on the working electrode surface of a screen-printed carbon electrode (SPCE), giving rise to the 2D Bi-exf-SPCE. It was microscopically and analytically examined and compared not only with bare SPCE but also with other bismuth-based screen-printed sensors that report good analytical performance, i.e., bismuth nanoparticle-modified SPCE (BiNP-SPCE) and sputtered bismuth SPE (BispSPE). Under improved conditions and for a 120 s preconcentration time, the sensor exhibits good correlation between peak area and metal concentration in the range 0.2-25.0 mu g L-1 for both Pb(II) and Cd(II) with LODs (3 times the standard deviation of the intercept over the slope of the linear calibration curve) of 0.06 and 0.07 mu g L-1 for Pb(II) and Cd(II), respectively. 2D Bi-exf-SPCE has been successfully applied to a certified estuarine water reference material with excellent trueness and remarkable reproducibility. (C) 2020 Elsevier Ltd. All rights reserved.