Electrochemical Studies of Biosensor Mediators

Abstract

Electrochemical mediators, redox-active compounds used as electron transfer shuttles, are required for various electrochemical applications such as fuel or photovoltaic cells and biosensors. Biosensors, in particular, benefit from mediators since there are a variety of biological compounds in need of sensing that are not electrochemically active or are difficult to elicit an electrochemical response from. Redox polymer mediators enhance the signal in existing sensor platforms and remove interference issues by shifting the potential at which the sensor operates. Oxygen contamination during the redox polymer synthesis led to a major product whose potential was ineffective at this task. Tagging analytes desired for detection with mediators was the basis for two different early sepsis intervention sensor attempts. One platform utilized ferrocene-encapsulated particles in a traditional antibody sandwich immunoassay. This sensor did not adhere to the electrode surface with multiple wash steps leading to problems with replication. Another platform used an indirect competitive electrochemical immunoassay for both a static and microfluidic platform with alkaline phosphatase reacting with ¬p-aminophenyl phosphate to create p-aminophenol, an electroactive compound. This compound was further studied due to its surface polymerization on the electrode surface. Concentration optimization was performed.