Effects of Potassium on the Supramolecular Structure and Electronic Properties of Eumelanin Thin Films

被引:12
作者
Borghetti, Patrizia [1 ]
Goldoni, Andrea [2 ]
Castellarin-Cudia, Carla [2 ]
Casalis, Loredana [2 ]
Herberg, Fabian [3 ]
Floreano, Luca [4 ]
Cossaro, Albano [4 ]
Verdini, Alberto [4 ]
Gebauer, Ralph [5 ,6 ]
Ghosh, Prasenjit [5 ]
Sangaletti, Luigi [1 ]
机构
[1] Univ Cattolica, Dipartimento Matemat & Fis, Brescia, Italy
[2] Sincrotrone Trieste ScPA, Trieste, Italy
[3] Humboldt Univ, Dept Phys, Berlin, Germany
[4] CNR IOM, Lab TASC, Trieste, Italy
[5] Abdus Salam Int Ctr Theoret Phys ICTP, Trieste, Italy
[6] IOM CNR, DEMOCRITOS, Trieste, Italy
关键词
MELANIN FILMS; BINDING; ORGANIZATION;
D O I
10.1021/la102973u
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The role of potassium in the formation of synthetic eumelanin aggregates is investigated by atomic force microscopy and soft-X-ray spectroscopy. Control over the thin film granularity is achieved by using K salts, in both drop casting and electrodeposition of eumelanin thin films. Further control over orientation is made possible by a suitable choice of the substrate: evidence of self-assembly is found for thin films deposited on gold. Finally, it is shown that the potassium content affects not only the samples morphology, but also the low-lying states in the valence band, where a transfer of spectral weight across the HOMO-LUMO gap is observed, disclosing possible applications of this multifunctional biomacromolecule.
引用
收藏
页码:19007 / 19013
页数:7
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