EventsDr. David Cahen

Electron Transport across Peptides and Proteins

Molecular electronics has as one of its goals to incorporate functional molecules into electrical circuits, to provide characteristics beyond those of existing and predicted semiconductor-based electronics.  Going from simple molecules to functional ones is, though, a huge step. This is where proteins come in and we move to bio-molecular electronics.

We and others have found that electron transport (ETp), i.e., electronic conduction, across proteins in a solid state–like configuration is surprisingly efficient, comparable to or, if length-normalized, at times even more efficient than via completely conjugated molecules.1 Working with modified proteins and homo-peptides we find that both cofactors and secondary structure matter for ETp efficiency.

While ET and ETp are related, nature regulates ET via redox chemistry, where control over the process is achieved at a price in free energy, while for ETp a redox process is not necessary. This allows studying ETp via non-redox proteins, such as the rhodopsins and albumins. This finding points to peptides as an efficient transport medium and I will cover their electronic transport behaviour, in addition to that of proteins.

1 N. Amdursky et al., Adv. Mater. 42,7142-7161(2014) Electronic Transport via Proteins 10.1002/adma.201402304

* collaboration with Profs. Mordechai Sheves & Israel Pecht. Work involved and involves former group members, Drs. R. Lovrincic, L. Sepunaru, Xi Yu, N. Amdursky, and present group members Drs. C. Guo, J. Fereiro, S. Mukhopadhyay. Computational theory was done by Prof. L. Kronik, Drs. P. Agrawal D. Egger & S. Refaely-Abramson, and Prof. Y. Levy and Y. Gavrilov from the Weizmann Inst. of Science.

About The Speaker

David Cahen studied chemistry & physics at Hebrew University of Jerusalem (HUJI), materials chemistry at Northwestern University, and, as PD, biophysics of photosynthesis at HUJI and Weizmann Institute of Science (WIS). After joining the WIS he specialized in alternative sustainable energy resources; his research today is on halide perovskite solar cells and on peptide & protein bio-optoelectronics and implications for electron transport across biomolecules. He is a fellow of AVS and MRS. He heads WIS’ Alternative, sustainable energy research initiative.