Synthesis of a novel hedgehog-shaped Bi2S3 nanostructure for a sensitive electrochemical glucose biosensor

Abstract

A novel hedgehog-shaped bismuth sulfide (HS-Bi₂S₃) nanostructure was for the first time explored as an electrode material for biosensing. Using cetyltrimethyl ammonium bromide (CTAB)-trimellitic acid as a composite soft template, the HS-Bi₂S₃ nanostructure was synthesized by a hydrothermal route. Using glucose oxidase (GOx) as the model, the HS-Bi₂S₃ nanostructure was employed to immobilize GOx for the development of a sensitive electrochemical glucose biosensor. The characterization of HS-Bi₂S₃ and the biosensor was performed by scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry. The hedgehog-shaped nanostructure of Bi₂S₃ has a large specific surface area to trap a large number of enzyme molecules, and at the same time greatly enhances the direct-electron-transfer action of enzymes. The HS-Bi₂S₃-based biosensor shows a wide linear range of 0.005–1.7 mmol L⁻¹ and a low detection limit of 1.6 μmol L⁻¹ for glucose at −0.37 V, which presents much better assay performance in comparison with the glucose biosensor without HS-Bi₂S₃. The present electrochemical biosensor displays high selectivity, good repeatability and stability, which can be used to measure blood glucose in real serum samples.