The influence of copper ions on the transport and relaxation properties of hydrated eumelanin

0571637 - FZÚ 2024 RIV GB eng J - Journal Article
Abramov, P. A. - Zhukov, S.S. - Savinov, Maxim - Mostert, A.B. - Motovilov, K.A.
The influence of copper ions on the transport and relaxation properties of hydrated eumelanin.
Physical Chemistry Chemical Physics. Roč. 25, č. 16 (2023), s. 11601-11612. ISSN 1463-9076. E-ISSN 1463-9084
Institutional support: RVO:68378271
Keywords : paramagnetic resonance spectroscopy * elecron spin resonance * x-ray characterization * melanin state proteins
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.3, year: 2022
Method of publishing: Limited access
https://doi.org/10.1039/d3cp00975k

Eumelanin, the human skin pigment, is a poly-indolequinone material possessing a unique combination of physical and chemical properties. For numerous applications, the conductivity of eumelanin is of paramount importance. However, its hydration dependent conductivity is not well studied using transport-relaxation methods. Furthermore, there is no such work taking into account the simultaneous control of humidity as well as metal ion concentration. Here we present the first such study of the transport and relaxation characteristics of synthetic eumelanin doped with various Cu ion concentrations while controlling the humidity with a frequency range of 10^(-3) Hz–1 MHz. We found that Cu ions do not cause the appearance of additional relaxation processes. In addition, the key relaxation process observed in doped and undoped materials is associated with the moisture-induced synthesis of uncharged semiquinones and a corresponding increase in the overall aromaticity of the material.
Permanent Link: https://hdl.handle.net/11104/0348926