Two types of bismuth modified electrodes, a bismuth-film modified glassy carbon (BiF-GCE) and a bismuth bulk modified carbon paste, were applied for the determination of selected nitroguanidine neonicotinoid insecticides. The method based on an ex situ prepared BiF-GCE operated in the differential pulse voltammetric (DPV) mode was applied to determine clothianidin in the concentration range from 2.5 to 23 μg cm⁻³ with a relative standard deviation (RSD) not exceeding 1.5%. The tricresyl phosphate-based carbon paste electrodes (TCP-CPEs), bulk modified with 5 and 20 w/w% of bismuth, showed a different analytical performance in the determination of imidacloprid, regarding the peak shape, potential window, and noise level. The TCP-CPE with 5% Bi was advantageous, and the developed DPV method based on it allowed the determination in the concentration range from 1.7 to 60 μg cm⁻³ with an RSD of 2.4%. To get a deeper insight into the morphology of the bismuth-based sensor surfaces, scanning electron microscopic measurements were performed of both the surface film and the bulk modified electrodes.

In this work, the use of square-wave adsorptive stripping voltammetry (SWAdSV) in combination with boron-doped diamond electrode modified with multiwalled carbon nanotubes (MWCNTs-BDDE) and β-cyclodextrin (β-CD, β-CD-MWCNTs-BDDE) for the determination of the fungicide carbendazim (Cbz) is described for the first time. Cbz oxidation response was observed in the Britton-Robinson buffer supporting electrolyte in a pH range from 2.3 to 6.0 in potential range from + 1.0 to + 1.3 V vs SCE. The SWAdSV peak current of Cbz oxidation response on β-CD-MWCNTs-BDDE with peak maxima close to + 1.2 V vs SCE at pH 4.0 was linear over the wide linear dynamic range of 6.72 × 10⁻⁷–1.12 × 10⁻⁵ mol L⁻¹ with a detection limit (LOD) of 1.96 × 10⁻⁷ mol L⁻¹. The obtained results demonstrated the viability of the proposed methodology for determination of Cbz in river water samples containing low concentrations of Cbz. Moreover, the effect of Cbz on the corrosion properties of an AISI type 316 L stainless steel used to fabricate farming equipment and tools was tested by means of the potentiodynamic method. The characterization and evaluation of the corrosion inhibition effect raised from the use of Cbz was performed using optical microscope.