A Facile Route to Synthesize DyF3/Bi2O3 Nanowires and Sensitive L-cysteine Sensing Properties

Abstract

DyF3/Bi2O3 nanowires with orthorhombic DyF3 and triclinic Bi2O3 phases were synthesized via a facile hydrothermal route using sodium dodecyl sulfate (SDS). The composite nanowires were characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. The obtained composite nanowires have the length of longer than 10 μm and diameter of about 20–100 nm. X-ray photoelectron spectroscopy confirms the composition of Dy, F, Bi and O in the composite nanowires. The formation process of the DyF3/Bi2O3 nanowires was analyzed based on the morphological and structural evolution of the products from different growth conditions. The cyclic voltammetry (CV) measurement demonstrates good electro-catalytic activity of the composite nanowires towards L-cysteine. Two pairs of CV peaks at +0.08 V, −0.43 V and −0.48 V, −0.78 V, respectively are observed at the DyF3/Bi2O3 nanowires modified glassy carbon electrode. DyF3/Bi2O3 nanowires modified glassy carbon electrode detects L-cysteine linearly over a concentration range from 0.001 to 2 mM with a detection limit of 0.25 μM. Moreover, the results show good selectivity, reproducibility and stability of the DyF3/Bi2O3 nanowires as a promising candidate for L-cysteine determination.