Fan Hailong, Yu Xiang, Liu Yang, Shi Zujin, Liu Huihui, Nie Zongxiu, Wu Decheng, Jin Zhaoxia
Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China.
Soft Matter. 2015 Jun 21;11(23):4621-9. doi: 10.1039/c5sm00732a.
Recent research has indicated that polydopamine and synthetic eumelanins are optoelectronic biomaterials in which one-dimensional aggregates composed of ordered-stacking oligomers have been proposed as unique organic semiconductors. However, improving the ordered-stacking of oligomers in polydopamine nanostructures is a big challenge. Herein, we first demonstrate how folic acid molecules influence the morphology and nanostructure of polydopamine via tuning the π-π interactions of oligomers. MALDI-TOF mass spectrometry reveals that porphyrin-like tetramers are characteristic of folic acid-polydopamine (FA-PDA) nanofibers. X-ray diffraction combined with simulation studies indicate that these oligomers favour aggregation into graphite-like ordered nanostructures via strong π-π interactions. High-resolution TEM characterization of carbonized FA-PDA hybrids show that in FA-PDA nanofibers the size of the graphite-like domains is over 100 nm. The addition of folic acid in polydopamine enhances the ordered stacking of oligomers in its nanostructure. Our study steps forward to discover the mystery of the structure-property relationship of FA-PDA hybrids. It paves a way to optimize the properties of PDA through the design and selection of oligomer structures.
近期研究表明，聚多巴胺和合成真黑素是光电生物材料，其中由有序堆叠的低聚物组成的一维聚集体被认为是独特的有机半导体。然而，改善聚多巴胺纳米结构中低聚物的有序堆叠是一项巨大挑战。在此，我们首次展示了叶酸分子如何通过调节低聚物的π-π相互作用来影响聚多巴胺的形态和纳米结构。基质辅助激光解吸电离飞行时间质谱表明，卟啉样四聚体是叶酸-聚多巴胺（FA-PDA）纳米纤维的特征。X射线衍射结合模拟研究表明，这些低聚物通过强π-π相互作用倾向于聚集成类石墨有序纳米结构。碳化FA-PDA杂化物的高分辨率透射电镜表征表明，在FA-PDA纳米纤维中，类石墨域的尺寸超过100nm。在聚多巴胺中添加叶酸可增强其纳米结构中低聚物的有序堆叠。我们的研究朝着揭示FA-PDA杂化物结构-性能关系的奥秘迈进。它为通过低聚物结构的设计和选择来优化聚多巴胺的性能铺平了道路。
