Jastrzebska M M, Isotalo H, Paloheimo J, Stubb H, Pilawa B
Department of Biochemistry and Biophysics, Silesian Medical Academy, Sosnowiec, Poland.
J Biomater Sci Polym Ed. 1996;7(9):781-93. doi: 10.1163/156856296x00129.
The purpose of the present study was to examine semiconductor properties of synthetic DOPA melanin, which are basic for future biological applications. DC conductivity, electron spin resonance (ESR), and atomic absorption spectroscopy (AAS) measurements have been performed to investigate the effect of Cu(2+)-ions on the semiconductor properties of melanin polymer synthesized from DOPA (3,4-dihydroxyphenylalanine). DOPA melanin - Cu2+ complexes examined show the decrease of both thermal activation energy delta Ea and pre-exponential factor sigma o values upon doping. At the same time no substantial changes in conductivity at 293 K have been observed. Formation of bipolaron states due to chelation of copper ions by melanin orthosemiquinones has been postulated. The Meyer-Neldel rule with a characteristic temperature T0 equal to 298 K and possible physiological implication of this fact are discussed. These data suggest, that DOPA melanin polymer could be useful as a type of culture substratum.
本研究的目的是研究合成多巴黑色素的半导体特性，这是其未来生物应用的基础。已进行直流电导率、电子自旋共振（ESR）和原子吸收光谱（AAS）测量，以研究Cu(2+)离子对由多巴（3,4-二羟基苯丙氨酸）合成的黑色素聚合物半导体特性的影响。所研究的多巴黑色素-Cu2+络合物在掺杂后热激活能δEa和指前因子σo值均降低。同时，在293K时未观察到电导率有实质性变化。推测黑色素邻半醌与铜离子螯合形成双极化子态。讨论了特征温度T0等于298K的迈耶-内德尔规则以及这一事实可能的生理意义。这些数据表明，多巴黑色素聚合物可用作一种培养底物。
