Centre for Organic Photonics and Electronics, School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia.
Langmuir. 2010 Jan 5;26(1):412-6. doi: 10.1021/la901290f.
The melanins are an important class of multifunctional biomacromolecules that possess a number of intriguing physical and chemical properties including electrical and photoconductivity. Unusually for a conducting organic material, eumelanin is hydrophilic and its electrical properties are strongly dependent on its hydration state. We have therefore measured adsorption isotherms for two polar adsorbates, water and ethanol, in the pressed powder pellets of synthetic eumelanin typically used in electrical studies. We show that a simple kinetic monolayer Langmuir model describes the adsorption and find that there are strong adsorbate-eumelanin interactions in both cases. These isotherms allow the proper scaling of electrical conductivity data and in doing so make progress toward a better understanding of eumelanin electrical properties, which is a critical prerequisite to the design of new eumelanin-like bioelectronic materials.
黑色素是一类重要的多功能生物大分子，具有许多有趣的物理和化学性质，包括电导率和光电导性。与通常的有机导电材料不同，真黑色素具有亲水性，其电学性质强烈依赖于其水合状态。因此，我们测量了两种极性吸附物（水和乙醇）在用于电学研究的合成真黑色素压粉颗粒中的吸附等温线。我们表明，简单的动力学单层朗缪尔模型可以描述吸附，并且在两种情况下都发现了强的吸附物-真黑色素相互作用。这些吸附等温线允许对电导率数据进行适当的缩放，并朝着更好地理解真黑色素的电学性质迈出了一步，这是设计新型真黑色素类生物电子材料的关键前提。
