CHARGE TRANSPORT IN SELF-ASSEMBLED PEPTIDE NANOSTRUCTURES

Inspired by the efficient charge transport in natural biological systems, the possibility of using peptides - short man-made proteins - as electronic materials, seems to be very attractive. Synthesis flexibility together with the ability of peptides to self-assemble into nanometric structures enables exploiting the advantages of both natural and synthetic organic materials. However, there are still open questions regarding charge transport phenomena in peptide nanostructures.

This research sheds light on the nature of charge transport in fibrous networks of amyloid β-based peptides, and the structural and environmental conditions that affect it. We demonstrate that the electronic conduction of the peptide nanostructures is improved by introducing non-natural amino acids or side chains to the peptide sequence.^1,2 Furthermore, we show that in similar to natural systems, both proton and electron charge carriers exist in these systems.² It is also shown that the solvent and self-assembly duration affect the resulting morphology, and hence, the electric properties. Particularly, we found that the finer and more homogenous the peptide fiber morphology is, the higher are both the conductance and its dependence on the relative humidity.^1,3

This research proves that by precise control of the peptide sequence and the procedure parameters used for the assembly, peptide fibrils can serve as a novel class of nano-materials in bioelectric applications.

References:

¹ Moran Amit, Ge Cheng, Ian W. Hamley, and Nurit Ashkenasy, Soft Matter 2012, 8, 8690.

² Moran Amit and Nurit Ashkenasy, Isr. J. Chem. 2014, 54, 703.

³ Moran Amit, Sagi Appel, Rotem Cohen, Ge Cheng, Ian W. Hamley, and Nurit Ashkenasy, Adv. Funct. Mater. 2014, 24, 5873.