Selection of a Bismuth Film Electrode for Simultaneous Voltammetric Detection of Heavy Metals as the Final Step of an Immunoassay with the Quantum Dots

Abstract

Solid glassy carbon (GCE), metal disk, and commercial screen-printed electrodes (SPEs) were tested as suitable substrate(s) for deposition of bismuth films. The respective bismuth film electrodes were then used for the simultaneous voltammetric detection of selected heavy metals that had simulated the dissolved quantum dots of the immunoassays known as QLISA. According to the results obtained, it has been found that selected commercial SPEs are not suitable electrode substrates due to a parasitic anodic peak at DRP-150 and DRP-250AT, having significantly increased the background current under repetition of the same measurement at DRP-110, as well as decomposition of the supporting electrolyte at highly negative potentials at DRP-250BT. Unlike metal disk electrodes, GCE coated with thin bismuth film was applicable up to ‒1.5 V.