Abstract
This study investigates the impact of different incubation times and concentrations of a self-assembled monolayer (SAMs) of 3-mercaptopropionic acid (MPA) on the rate of electron transfer in redox processes. The aim is to understand how these parameters can affect the sensitivity and efficiency of biosensors based on direct electron transfer in redox proteins. Through a series of experiments, different incubation times and concentrations of MPA were examined to determine their impact on the electron-transfer rate. Using methylene blue MB molecules as a model system and employing the EC-SPR technique, the reflectance differences (ΔR) between the reduced and oxidized states of MB were analyzed, serving as an indicator of the electron transfer rate. The results revealed significant variations in the rate depending on the incubation times and concentrations of the MPA. It was determined that a combination of 1 mM MPA concentration and 6-hour incubation time provided optimal conditions for maintaining a significant (ΔR). These findings have important implications for optimizing sensor surfaces in biosensors based on direct electron transfer in redox proteins.