Electron Hopping Across Hemin-Doped Serum Albumin Mats on Centimeter-Length Scales

5 years ago

Electron Hopping Across Hemin-Doped Serum Albumin Mats on Centimeter-Length Scales

D. Jason Riley, Molly M. Stevens, David J. Payne, Xuhua Wang, Paul Meredith, Donal D. C. Bradley, Nadav Amdursky

Exploring long-range electron transport across protein assemblies is a central interest in both the fundamental research of biological processes and the emerging field of bioelectronics. This work examines the use of serum-albumin-based freestanding mats as macroscopic electron mediators in bioelectronic devices. In particular, this study focuses on how doping the protein mat with hemin improves charge-transport. It is demonstrated that doping can increase conductivity 40-fold via electron hopping between adjacent hemin molecules, resulting in the highest measured conductance for a protein-based material yet reported, and transport over centimeter length scales. The use of distance-dependent AC impedance and DC current–voltage measurements allows the contribution from electron hopping between adjacent hemin molecules to be isolated. Because the hemin-doped serum albumin mats have both biocompatibility and fabrication simplicity, they should be applicable to a range of bioelectronic devices of varying sizes, configurations, and applications. Protein-based free-standing mats can be used as macroscopic electron mediators. This study demonstrates how molecular doping of protein mats with hemin permits electron hopping between hemin molecules and results in the highest measured centimeter-length conductance for a protein-based material yet reported. The hemin-doped protein mats display both biocompatibility and fabrication simplicity, which present advantages for their use in bioelectronic devices.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201700810