456 Nanosensors: Physical, Chemical, and Biological
of proteins and electrodes. Thus they act as “electron wires” favoring elec-
tron transfer in these applications.
How is the insulating effect of protein shell reduced by gold NPs? Modication of
electrode surfaces with gold NPs provides a sympathetic microenvironment
similar to that of the redox proteins in native systems, giving the protein
molecules more liberty in orientation, thereby reducing the insulating effect
of the protein shell for the direct electron ferrying through the conducting
passageways or tunnels of gold nanocrystals. It is believed that the nano-
metric edges of gold particles penetrate slightly into the protein, thereby
decreasing the distance between the elect ...