Fabrication of New GH-CS/Fc-NH2/Cytc Modified Electrode and Its Application in Detection of Nitrite

Highly conjugated linear molecular wires are one of the basic elements for constructing molecular electronic devices. Among these conjugated compounds, ferrocene-terminated compounds as well as their derivatives were widely studied because of their ideal electrochemical activity. Based on these, a new ferrocene-terminated phenylethynyaniline (Fc-NH2) was synthesized by Sonogashira cross coupling reaction. The structure of the target compound was identified by infrared (IR), nuclear magnetic resonance (NMR), mass spectra (MS) and cyclic voltammetry (CV). By combining the graphene-chitosan (GH-CS) and Fc-NH2, a new composite of GH-CS/Fc-NH2 was prepared and then used for immobilization of Cytc to prepare the GH-CS/Fc-NH2/cytochrome c (Cytc)/GCE. It was found from the CV result that a pair of peaks near. -0.2 V was appeared, which could be attributed to Cytc. The GH-CS/Fc-NH2/Cytc modified GCE shows good catalysis towards NaNO2, and good linear relationship was found in the range of 1.0 x 10(-7-)1.5 x 10(-4) M with the detection limit bellow 4.0 x 10(-8) M. Therefore, Cytc could be immobilized on the GH-CS/Fc-NH2 and the direct electron transfer was realized between the electrode and solution, and showed good prospect for detection of NaNO2.