The application of bismuth film electrode for measuring Zn(II) under less acidic conditions in the presence of cell culture medium and ZnO nanoparticles

Abstract

A study for the application of bismuth film electrode (BiFE) under less acidic conditions for anodic stripping voltammetric measurements of Zn(II) in complex organic sample, i.e. in the cell culture medium containing ZnO nanoparticles, is presented. The BiFE was prepared in-situ on a substrate glassy carbon electrode in solution containing 0.1molL−1 piperazine-N,N'-bis(2-ethanesulfonic acid) (PIPES) and 0.1molL−1 KNO3 as supporting electrolyte, adjusted to pH 6.5, and in the presence of dissolved oxygen. In the model solution, i.e. in the absence of cell culture medium and ZnO nanoparticles, the BiFE revealed good linear response in the examined concentration range of 10–100μgL−1 Zn(II) with r2 of 0.994, the LOD of 0.14μgL−1 associated with 120s accumulation step, and favorable repeatability of 1.7%. Upon the addition of cell culture medium, the signal of Zn(II) attenuated for ca. 64%; however, the BiFE still exhibited excellent linear response in the examined concentration range of 10–100μgL−1 Zn(II) with r2=0.999, favorably low LOD of 0.15μgL−1 after 120s accumulation, and satisfactory repeatability of 3.0%. Finally, the applicability of the proposed method was successfully demonstrated through measuring Zn(II) in the cell culture medium containing 5mgL−1 of ZnO nanoparticles for the purpose of a nanotoxicological study.