Ultra-selective, trace level detection of As3+ ions in blood samples using PANI coated BiVO4 modified SPCE via differential pulse anode stripping voltammetry.

We report a novel, facile hydrothermal synthesis of bismuth vanadate (BiVO4) nanoflakes coated with polyaniline (PANI) via electrodeposition on screen-printed carbon electrode (SPCE) for trace level detection of arsenic in biological samples. The crystallinity and monoclinic scheelite structure of as-synthesised BiVO4 nanoflakes was analysed using X-Ray diffraction (XRD) and the surface morphology and chemical analysis of the flake-like BiVO4 and PANI coated BiVO4 modified SPCE (PANI@BiVO4/SPCE) were studied using Field emission scanning electron microscopy (FESEM), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The presence of VO4 tetrahedra and VO43- group along with oxy-functional groups were confirmed using Raman and FTIR analysis, respectively. Under optimized conditions, the sensor could detect As3+ ions via differential pulse anodic stripping voltammetry (DPASV) technique with remarkable low limit of detection (LOD) of 0.0072 ppb (which is far below the MCL testified values) and exhibited a sensitivity of 6.06 μA ppb-1 cm-2 for a linear range of 0.01 to 300 ppb. This improved sensing aptitude can be ascribed to the synergetic effect of PANI and BiVO4 by providing high electrical conductivity and high electrocatalytic active sites via VO43- tetrahedra, respectively. The sensor showed an outstanding selectivity in detection of As3+ ions in trace levels in simulated blood serum samples with excellent recovery percentages thus making it an ideal platform to develop numerous electrochemical sensing platforms for bioanalytical applications.