Preparation and Characterization of a Tin Pentacyanonitrosylferrate-Modified Carbon Ceramic Electrode: Application to Electrocatalytic Oxidation and Amperometric Detection of L-Cysteine

摘要

The sol-gel technique was used to construct tin pentacyanonitrosylferrate (SnPCNF) modified composite carbon ceramic electrode (CCE). This involves two steps: construction of CCE containing metallic Sn powder and then electrochemical creating of SnPCNF on the surface of CCE. The SnPCNF modified CCE (SnPCNF1CCE) was characterized by energy-dispersive X-ray (EDX), FTIR and cyclic voltammetry (CV) techniques. The SnPCNF film showed electrocatalytic activity toward the oxidation of L-cysteine. A linear calibration plot was obtained over the Lcysteine concentration range 1- 51 μМ using chronoamperometry. L-cysteine was determined amperometrically at the surface of this modified electrode. The detection limit (for a signal to noise of 3) and sensitivity were found to be 0.62 μM and 126 μA/mM, respectively.