Facile method to synthesize graphene-ZnS nanocomposites: preparation and application in bioelectrochemistry of hemoglobin

A novel electrochemical platform based on ZnS-doped graphene (GR-ZnS) nanocomposites was developed to achieve the direct electron transfer between hemoglobin (Hb) and the modified electrode. GR-ZnS nanocomposites were synthesized via noncovalent functionalization of pristine graphene (GR) by 1-aminopyrene and subsequent in situ synthesis of ZnS nanoparticles on the GR surface. During this process, the intrinsic electronic properties of GR could be efficiently protected. The as-prepared GR-ZnS nanocomposites were characterized and identified by means of transmission electron microscopy and energy dispersive X-ray spectrometer analysis, indicating the uniform formation of ZnS nanoparticles on the surface of GR. Fourier transform infrared spectra spectroscopic results confirmed that Hb remained its native structure in the nanocomposite material. The GR-ZnS nanocomposites could efficiently promote the direct electron transfer between Hb and electrode with the electron transfer rate constant ( k s ) of 3.42 s −1 . The modified electrode was then used for the determination of H 2 O 2 based on the electrocatalytic activity of Hb towards H 2 O 2 , which exhibited a linear range from 10 to 250 μM with a detection limit of 1.12 μM. The proposed method to fabricate GR-based hybrid nanomaterials would have a great potential for applications in various fields such as electrochemical sensing, catalytic reaction, and super capacitors.