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 ZnCl(2) and SnCl(2) 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 (H(2)O(2)) 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 (E(0')) of -0.40 V and a peak-to-peak separation (ΔE(p)) of 0.086 V. Moreover, the biosensor exhibited an excellent electrocatalytic activity to H(2)O(2) with a K(M) value of 0.379 mM; the reduction peak currents of Hb on the Hb/Zn-SnNPs/MWNTs/GCE were linearly related to H(2)O(2) 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 H(2)O(2) biosensors and provided a way to develop other biologic active materials in ionic liquids.