Synthesis of Polyaniline/BiPr Composite Oxide Nanowires with Enhanced Electrochemical Sensing Performance

Background: Considerable interest has been devoted to electrochemical sensors for the detection of L-cysteine using BiPr-based oxide-modified electrodes due to high specific surface area and good electro-catalytic activity with several oxidation states. The combination of the BiPr composite oxide nanowires with polyaniline (PAn) can promote the electro-catalytic performance towards L-cysteine because PAn can facilitate the electro-catalytic process by enhancing the charge transfer. Methods: PAn/BiPr composite oxide nanowires were obtained via low temperature one-step hydrothermal route. The obtained composite oxide nanowires were analyzed by X-ray diffraction, electron microscopy, and electrochemical methods. Results: Characterization results indicate that amorphous PAn nanoparticles with a size of about 50 nm are homogeneously dispersed at the surface of the BiPr composite oxide nanowires. PAn/BiPr composite oxide nanowire-modified electrode shows an enhanced L-cysteine electro-catalytic activity. PAn promotes electro-catalytic activity of the BiPr composite oxide nanowires. A pair of quasi-reversible cyclic voltammetry (CV) peaks exist at +0.49 V, -0.19 V, respectively. PAn/BiPr composite oxide nanowire modified electrode possesses a linear response in L-cysteine concentration of 0.001-2 mM and detection limit of 0.095 μM, good repeatability, and stability. Conclusion: PAn/BiPr composite oxide nanowires act as effective electro-catalysts for L-cysteine oxidation resulting in the enhancement of the electro-catalytic activity relative to BiPr composite oxide nanowires.