Issue 13, 2020

Exploring long-range proton conduction, the conduction mechanism and inner hydration state of protein biopolymers

Abstract

Proteins are the main proton mediators in various biological proton circuits. Using proteins for the formation of long-range proton conductors is offering a bioinspired approach for proton conductive polymers. One of the main challenges in the field of proton conductors is to explore the local environment within the polymers, along with deciphering the conduction mechanism. Here, we show that the protonic conductivity across a protein-based biopolymer can be hindered using straightforward chemical modifications, targeting carboxylate- or amine-terminated residues of the protein, as well as exploring the effect of surface hydrophobicity on proton conduction. We further use the natural tryptophan residue as a local fluorescent probe for the inner local hydration state of the protein surface and its tendency to form hydrogen bonds with nearby water molecules, along with the dynamicity of the process. Our electrical and spectroscopic measurements of the different chemically-modified protein materials as well as the material at different water–aprotic solvent mixtures result in our fundamental understanding of the proton mediators within the material and gaining important insights on the proton conduction mechanism. Our biopolymer can be used as an attractive platform for the study of bio-related protonic circuits as well as a proton conducting biopolymer for various applications, such as protonic transistors, ionic transducers and fuel cells.

Graphical abstract: Exploring long-range proton conduction, the conduction mechanism and inner hydration state of protein biopolymers

Associated articles

Supplementary files

Article information

Article type
Edge Article
Submitted
01 Sep 2019
Accepted
06 Mar 2020
First published
11 Mar 2020
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2020,11, 3547-3556

Exploring long-range proton conduction, the conduction mechanism and inner hydration state of protein biopolymers

S. Mondal, Y. Agam, R. Nandi and N. Amdursky, Chem. Sci., 2020, 11, 3547 DOI: 10.1039/C9SC04392F

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements