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

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 VO₄^3- 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 VO₄^3- 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.