School of Science, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia.
School of Chemical Sciences, Goa University, Taleigao Plateau, Goa 403206, India.
Molecules. 2019 Nov 18;24(22):4172. doi: 10.3390/molecules24224172.
The fabrication of controlled supramolecular nanostructures via self-assembly of protoporphyrin IX (PPIX) was studied with enantiomerically pure l-arginine and d-arginine, and we have shown that stoichiometry controlled the morphology formed. The nanostructure morphology was mainly influenced by the delicate balance of π-π stacking interactions between PPIX cores, as well as H-bonding between the deprotonated acidic head group of PPIX with the guanidine head group of arginine. PPIX self-assembled with l-/d-arginine to create rose-like nanoflower structures for four equivalents of arginine that were 5-10 μm in length and 1-4 μm diameter. We employed UV-vis, fluorescence spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR) techniques to characterize the resulting self-assembled nanostructures. Furthermore, we investigated the catalytic activity of PPIX and arginine co-assembled materials. The fabricated PPIX-arginine nanostructure showed high enhancement of photocatalytic activity through degradation of rhodamine B (RhB) with a decrease in dye concentration of around 78-80% under simulated visible radiation.
通过原卟啉 IX（PPIX）的自组装来制造受控的超分子纳米结构，使用对映体纯的 l-精氨酸和 d-精氨酸进行了研究，我们已经表明，化学计量比控制了形成的形态。纳米结构形态主要受到 PPIX 核之间的π-π堆积相互作用的微妙平衡以及 PPIX 的去质子酸性头基团与精氨酸的胍基之间的氢键的影响。PPIX 与 l-/d-精氨酸自组装，为四个当量的精氨酸形成了玫瑰花状的纳米花结构，长度为 5-10μm，直径为 1-4μm。我们采用了紫外-可见、荧光光谱、扫描电子显微镜（SEM）、X 射线衍射（XRD）、动态光散射（DLS）和傅里叶变换红外光谱（FT-IR）技术来表征所得的自组装纳米结构。此外，我们研究了 PPIX 和精氨酸共组装材料的催化活性。所制备的 PPIX-精氨酸纳米结构在模拟可见光辐射下通过罗丹明 B（RhB）的降解表现出高的光催化活性增强，染料浓度降低约 78-80%。
