Journal article 1190 views
Role of semiconductivity and ion transport in the electrical conduction of melanin
,
Bernard Mostert
Proceedings of the National Academy of Sciences, Volume: 109, Issue: 23, Pages: 8943 - 8947
Swansea University Authors:
Paul Meredith , Bernard Mostert
Full text not available from this repository: check for access using links below.
DOI (Published version): 10.1073/pnas.1119948109
Abstract
Melanins are pigmentary macromolecules found throughout the biosphere that, in the 1970s, were discovered to conduct electricity and display bistable switching. Since then, it has been widely believed that melanins are naturally occurring amorphous organic semiconductors. Here, we report electrical...
| Published in: | Proceedings of the National Academy of Sciences |
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| ISSN: | 0027-8424 1091-6490 |
| Published: |
2012
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| Online Access: |
Check full text
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| URI: | https://cronfa.swan.ac.uk/Record/cronfa38486 |
| Abstract: |
Melanins are pigmentary macromolecules found throughout the biosphere that, in the 1970s, were discovered to conduct electricity and display bistable switching. Since then, it has been widely believed that melanins are naturally occurring amorphous organic semiconductors. Here, we report electrical conductivity, muon spin relaxation, and electron paramagnetic resonance measurements of melanin as the environmental humidity is varied. We show that hydration of melanin shifts the comproportionation equilibrium so as to dope electrons and protons into the system. This equilibrium defines the relative proportions of hydroxyquinone, semiquinone, and quinone species in the macromolecule. As such, the mechanism explains why melanin at neutral pH only conducts when “wet” and suggests that both carriers play a role in the conductivity. Understanding that melanin is an electronic-ionic hybrid conductor rather than an amorphous organic semiconductor opens exciting possibilities for bioelectronic applications such as ion-to-electron transduction given its biocompatibility. |
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| Keywords: |
bioelectronics, electrical properties, biomacromolecules, ionic conduction |
| College: |
Faculty of Science and Engineering |
| Issue: |
23 |
| Start Page: |
8943 |
| End Page: |
8947 |