A novel hydrogen peroxide biosensor based on the Sn–ZnNPs/MWNTs nanocomposite film

The Zn–Sn nanoparticles/multiwall carbon nanotubes (Zn–SnNPs/MWNTs) nanocomposite film was prepared by electrodeposition of ZnCl2 and SnCl2 on MWNTs simultaneously in Ethaline ionic liquids. Then, based on immobilizing hemoglobin (Hb) within a novel Zn–SnNPs/MWNTs nanocomposite film (Hb/Zn–SnNPs/MWNTs), a novel hydrogen peroxide (H2O2) biosensor was constructed. Meantime, the morphology of the Zn–SnNPs and analytical characteristics of the biosensor were investigated. A high density and well-distributed Zn–SnNPs spheres with an average diameter of 120 nm was observed by field emission scanning electron microscopy. The voltammetric results of the biosensor showed a pair of well-defined and quasi-reversible redox peaks of Hb with a formal potential (E0′) of −0.40 V and a peak-to-peak separation (ΔEp) of 0.086 V. Moreover, the biosensor exhibited an excellent electrocatalytic activity to H2O2 with a KM value of 0.379 mM; the reduction peak currents of Hb on the Hb/Zn–SnNPs/MWNTs/GCE were linearly related to H2O2 in the range from 0.5 to 840 μM with a correlation coefficient of 0.9984 and a detection limit of 0.11 μM (S/N = 3). Results demonstrated that Zn–SnNPs/MWNTs nanocomposite film was promising a new platform for the construction of H2O2 biosensors and provided a way to develop other biologic active materials in ionic liquids.