Direct electron transfer of cytochrome c immobilized on a NaY zeolite matrix and its application in biosensing

The immobilization and electrochemical behaviors of cytochrome c on a NaY zeolite modified electrode were studied. The interaction between cytochrome c and NaY zeolite particles was examined by using UV-Vis spectroscopy and electrochemical methods. The direct electron transfer of the immobilized cytochrome c exhibited a pair of redox peaks with the E_1/2 of -(44±3)mV (versus SCE) in 0.1M pH 7.0 PBS. The electrode reaction showed a surface-controlled process with a single proton transfer at the scan rate range from 20 to 500mVs^-1. Based on the immobilization of cytochrome c on NaY zeolite a high performance biosensor was constructed, which displayed an excellent response to the reduction of hydrogen peroxide (H₂O ₂) without the aid of an electron mediator and could be used for H₂O₂ detection. NaY zeolite provided a good matrix for protein immobilization and biosensor preparation.