Heme bound amylin self-assembled monolayers on an Au electrode: an efficient bio-electrode for O2 reduction to H2O.

Self-assembled monolayers of the water soluble hydrophilic part of naturally occurring amylin and its Arg11 mutant have been assembled on an Au surface, which are found to efficiently catalyze selective 4e(-)/4H(+) O2 reduction reaction (ORR) upon binding heme with a kcat of ∼10(7) M(-1) s(-1) under ambient conditions, where the Arg11 residue plays the key role of proton transfer in determining the rate of ORR.