Ozhukil Kollath Vinayaraj, Derakhshandeh Maziar, Mayer Francis D, Mudigonda Thanmayee, Islam Muhammad Naoshad, Trifkovic Milana, Karan Kunal
Department of Chemical and Petroleum Engineering, The University of Calgary 2500 University Drive N.W. Calgary Alberta T2N 1N4 Canada
RSC Adv. 2018 Sep 13;8(56):31967-31971. doi: 10.1039/c8ra05372c. eCollection 2018 Sep 12.
Shape and size controlled nanostructures are critical for nanotechnology and have versatile applications in understanding interfacial phenomena of various multi-phase systems. Facile synthesis of fluorescent nanostructures remains a challenge from conventional precursors. In this study, bio-inspired catecholamines, dopamine (DA), epinephrine (EP) and levodopa (LDA), were used as precursors and fluorescent nanostructures were synthesized a simple one pot method in a water-alcohol mixture under alkaline conditions. DA and EP formed fluorescent spheres and petal shaped structures respectively over a broad spectrum excitation wavelength, whereas LDA did not form any particular structure. However, the polyepinephrine (PEP) micropetals were formed by weaker interactions as compared to covalently linked polydopamine (PDA) nanospheres, as revealed by NMR studies. Application of these fluorescent structures was illustrated by their adsorption behavior at the oil/water interface using laser scanning confocal microscopy. Interestingly, PDA nanospheres showed complete coverage of the oil/water interface despite its hydrophilic nature, as compared to hydrophobic PEP micropetals which showed a transient coverage of the oil/water interface but mainly self-aggregated in the water phase. The reported unique fluorescent organic structures will play a key role in understanding various multi-phase systems used in aerospace, biomedical, electronics and energy applications.
形状和尺寸可控的纳米结构对纳米技术至关重要，并且在理解各种多相系统的界面现象方面具有广泛的应用。从传统前驱体制备荧光纳米结构仍然是一个挑战。在本研究中，受生物启发的儿茶酚胺，多巴胺（DA）、肾上腺素（EP）和左旋多巴（LDA）被用作前驱体，在碱性条件下于水 - 醇混合物中通过简单的一锅法合成荧光纳米结构。DA和EP分别在宽光谱激发波长下形成荧光球体和花瓣状结构，而LDA未形成任何特定结构。然而，核磁共振研究表明，与共价连接的聚多巴胺（PDA）纳米球相比，聚肾上腺素（PEP）微花瓣是通过较弱的相互作用形成的。利用激光扫描共聚焦显微镜观察这些荧光结构在油/水界面的吸附行为，说明了它们的应用。有趣的是，与疏水性的PEP微花瓣相比，PDA纳米球尽管具有亲水性，但却能完全覆盖油/水界面，而PEP微花瓣仅对油/水界面有短暂覆盖，且主要在水相中自聚集。所报道的独特荧光有机结构将在理解用于航空航天、生物医学、电子和能源应用的各种多相系统中发挥关键作用。
