A high-sensitive and fast-fabricated glucose biosensor based on Prussian blue/topological insulator Bi2Se3 hybrid film

A novel and fast-fabricated Prussian blue (PB)/topological insulator Bi2Se3 hybrid film has been prepared by coelectrodeposition technique. Taking advantages of topological insulator in possessing exotic metallic surface states with bulk insulating gap, Prussian blue nanoparticles in the hybrid film have smaller size as well as more compact structure, showing excellent pH stability even in the alkalescent solution of pH 8.0. Based on the Laviron theory, the electron transfer rate constant of PB/Bi2Se3 hybrid film modified electrode was calculated to be 4.05±0.49 s−1, a relatively big value which may be in favor of establishing a high-sensitive biosensor. An amperometric glucose biosensor was then fabricated by immobilizing glucose oxidase (GOD) on the hybrid film. Under the optimal conditions, a wide linear range extending over 3 orders of magnitude of glucose concentrations (1.0×10−5–1.1×10−2 M) was obtained with a high sensitivity of 24.55 μA mM−1 cm−2. The detection limit was estimated for 3.8 μM defined from a signal/noise of 3. Furthermore, the resulting biosensor was applied to detect the blood sugar in human serum samples without any pretreatment, and the results were comparatively in agreement with the clinical assay.

► Topological insulator (TI) Bi2Se3 has metallic surface with insulating bulk and we apply it.
► Coelectrodepositon was used to form PB/Bi2Se3 hybrid film, playing the role of TI.
► Bi2Se3 is conducive to form smaller PB nanoparticles and a smoother hybrid film.
► The hybrid film show excellent pH stability even in the alkalescent solution of pH 8.
► Fabrication of the hybrid film based biosensor is fast and it has potential practical utility.