Development of a Cytochrome c Oxidase Based Sensor for Monitoring Respiration and Metabolism

摘要

Electrodes modified with bilayers that incorporate cytochrome c oxidase (CCO), the terminal enzyme in mammalian respiration, will be studied as biosensors for cyanide. This CCO modified electrode has an architecture that exhibits robust response behavior and stability that mimics the in vivo behavior of this enzyme. These CCO modified electrodes remain active on storage in buffer, can withstand exposure to temperatures as extreme as 80 deg C (176 deg F) and have a functional lifetime exceeding two months. The structure of the CCO modified electrode proposed for study here is uniquely similar to its in vivo environment in the inner mitochondrial membrane. No other enzyme modified electrodes reported thus far in the literature has this structure. Experiments have shown that the electrochemical response of these CO modified electrodes to the oxidation of reduced cytochrome c (its reductive reaction partner) is sensitive to cyanide and the response is reversible. Work proposed here will characterize the affect of cyanide on the direct electron transfer reaction of these CCO modified electrode with ambient dioxygen concentrations (its oxidative reaction partner). Initial experiments testing this hypothesis have been positive. This is a simpler biosensor configuration compared with the cytochrome c system described above (no added component) and it has potential for providing a practical sensors with failure to military applications for toxins that inhibit the electron transfer reactions of CCO with lethal consequences.