Nanomolar detection of hydrogen peroxide at a new polynuclear cluster of tin pentacyanonitrosylferrate nanoparticle-modified carbon ceramic electrode.

This work describes a new electrochemical sensor for hydrogen peroxide based on tin pentacyanonitrosylferrate (SnPCNF)-modified carbon ceramic electrode (CCE). The modified electrode was constructed by using a sol-gel technique involving two steps: construction of CCE containing metallic tin (Sn) powder and then electrochemical creation of SnPCNF film on the surface of CCE. The modified electrode was characterized by energy-dispersive X-ray, Fourier transform infrared, scanning electron microscopy, and cyclic voltammetry (CV) techniques. The charge transfer coefficient (alpha) and charge transfer rate constant (k(s)) for the modifying film were calculated. The electrocatalytic activity of the modified electrode toward the reduction of hydrogen peroxide was studied by CV and chronoamperometry. A linear calibration curve was obtained over the hydrogen peroxide concentration range of 0.5 to 69.4 microM using a hydrodynamic amperometric technique. The limit of detection (for a signal-to-noise ratio of 3) and sensitivity were found to be 92 nM and 0.89 microA/microM, respectively. Furthermore, the diffusion coefficient of hydrogen peroxide (D) and catalytic rate constant (k(cat)) were calculated.