A novel bismuth imidazolate-based sensor for detection of trace lead(II)

Abstarct A new type of bismuth electrode (BiImE) for anodic stripping voltammetric detection of trace Pb(II), which is based on a bismuth imidazolate (BiIm) sensing coating, is presented. A simple preparation protocol was adopted via drop-casting a rapidly drying methanol suspension of amorphous BiIm, serving as a source of bismuth ions, onto a supporting glassy carbon electrode. The BiIm sensing material was characterized and several key parameters influencing the preparation and performance of BiImE were investigated. The BiImE revealed good linear response in the two examined concentration ranges of 10–100 μg L −1 and 1–10 μg L −1 with r 2 of 0.998 and 0.995, respectively, a low limit of detection (3σ) of 0.1 μg L −1 Pb(II) associated with 240 s accumulation, and a favorable repeatability with RSD of 3.8%. Even after scanning the potential toward more positive values than the re-oxidation potential of bismuth, the BiImE could be reused several times without any significant loss of performance, hence making it superior compared to its ex situ prepared counterparts while exhibiting advantages of the in situ prepared analogues. The applicability of BiImE was demonstrated through measuring Pb(II) in a real tap water sample. Preliminary experiments also proved its suitability for simultaneous measurement of trace Pb(II) and Cd(II).