Roy Subhasish, Maiti Dibakar Kumar, Panigrahi Shrabani, Basak Durga, Banerjee Arindam
Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
Phys Chem Chem Phys. 2014 Apr 7;16(13):6041-9. doi: 10.1039/c3cp55108c.
Self-assembled bolaamphiphilic perylene bisimide (PBI) containing an amino acid appended fluorescent semiconducting soft material (hydrogel) has been discovered at physiological pH. This new organic material based on self-assembled perylene bisimide appended amino acid-based bolaamphiphile (PBI-C11-Y) has been well characterized using various techniques including UV-Vis, fluorescence, X-ray diffraction, FT-IR, transmission electron microscopic (TEM) and atomic force microscopic (AFM) studies. Interestingly, the UV-Vis absorption properties of the soft-material are dependent on the pH of the medium. This PBI-conjugated amino acid appended gelator molecule contains a centrally located perylene bisimide moiety as well as an aromatic amino acid l-tyrosine at the side chains, which are extremely useful for interacting with the delocalized large π-surface of GO (graphene oxide) or RGO (reduced graphene oxide) to form a GO/RGO containing hybrid hydrogel. Graphene oxide and reduced graphene oxide have been successfully incorporated into the nanofibrillar network structure of the PBI-C11-Y based gel to make nanohybrid systems. The I-V profile of the semiconducting photo-responsive soft-material of the PBI-C11-Y has been successfully tuned upon the incorporation of GO and RGO within the gel-based soft material. This PBI-C11-Y xerogel based structure shows photo-switching behaviour upon exposure to white light. The ON/OFF ratio of the PBI-C11-Y can be modulated upon the inclusion of GO and RGO within the hydrogel matrix. Furthermore, the OFF state stability of the PBI-C11-Y xerogel material has been increased upon the inclusion of RGO. Regulation of the photo-switching behaviour of the PBI-C11-Y based xerogel holds promise for making PBI-containing amino acid appended biomaterials with interesting properties in future.
在生理pH值条件下，人们发现了一种自组装的含氨基酸的苝双酰亚胺（PBI）荧光半导体软材料（水凝胶）。这种基于自组装苝双酰亚胺连接氨基酸的双亲性分子（PBI-C11-Y）的新型有机材料已通过多种技术进行了充分表征，包括紫外可见光谱、荧光光谱、X射线衍射、傅里叶变换红外光谱、透射电子显微镜（TEM）和原子力显微镜（AFM）研究。有趣的是，这种软材料的紫外可见吸收特性取决于介质的pH值。这种PBI共轭氨基酸连接的凝胶剂分子在中心位置含有一个苝双酰亚胺部分，以及侧链上的芳香族氨基酸L-酪氨酸，这对于与氧化石墨烯（GO）或还原氧化石墨烯（RGO）的离域大π表面相互作用以形成含GO/RGO的杂化水凝胶极为有用。氧化石墨烯和还原氧化石墨烯已成功地掺入到基于PBI-C11-Y的凝胶的纳米纤维网络结构中，制成了纳米杂化体系。在基于凝胶的软材料中掺入GO和RGO后，成功地调节了PBI-C11-Y半导体光响应软材料的I-V曲线。这种基于PBI-C11-Y干凝胶的结构在暴露于白光时表现出光开关行为。通过在水凝胶基质中加入GO和RGO，可以调节PBI-C11-Y的开/关比。此外，加入RGO后，PBI-C11-Y干凝胶材料的关态稳定性得到了提高。调节基于PBI-C11-Y的干凝胶的光开关行为有望在未来制造出具有有趣特性的含PBI氨基酸连接生物材料。
