Department of Chemical and Pharmaceutical Sciences, INSTM UdR Trieste, Via Licio Giorgieri 1 , University of Trieste , 34127 Trieste , Italy.
Carbon Bionanotechnology Laboratory , CIC biomaGUNE , Paseo de Miramón 182 , 20014 Donostia-San Sebastián , Spain.
Acc Chem Res. 2019 Aug 20;52(8):2070-2079. doi: 10.1021/acs.accounts.9b00249. Epub 2019 Jul 23.
Over the past decades, considerable efforts have been devoted to synthesizing nanostructured materials with specific properties that ultimately shape their function. In the carbon nanotechnology era, for nanomaterials such as fullerenes, carbon nanotubes, and graphene, the main focus has been on the organic functionalization of these nanostructures, in order to tailor their processability and applicability. Carbon-based dots, quasi-spherical nanoparticles with a shape under 10 nm, have popped up into this context especially due to their versatile synthesis and intriguing properties, mainly their fluorescence emission. Even though they were discovered through the top-down route of cutting large carbon nanostructures, in recent years the ease and flexibility of the bottom-up synthesis have allowed this carbon-based class of nanomaterials to advance at a striking pace. However, the fast speed of research and publication rate have caused a few issues that affect their classification, purity criteria, and fluorescence mechanisms. As these are being progressively addressed, the true potential and applicability of this nanomaterial has started to unravel. In this Ariticle, we describe our efforts toward the synthesis, purification, characterization, and applications of carbon nanodots. Special attention was dedicated to designing and customizing the optoelectronic properties of these nanomaterials, as well as their applications in hybrid and composite systems. Our approach is centered on a bottom-up, microwave-assisted hydrothermal synthesis. We have successfully exploited a multicomponent synthetic approach, using arginine and ethylenediamine as starting materials. By controlling the reaction conditions, in just 3 min, blue-emitting carbon nanodots become accessible. We have improved this approach by designing and tuning the emissive, electrochemical, and chiroptical properties of these nanoforms. On the other hand, we have used postfunctionalization reactions as a tool for conjugation with suitable partners and for further tuning the surface chemistry. The combination of these two approaches has produced a number of carbon nanodots that can be investigated in fields ranging from biology to materials chemistry and in applications spanning from nanomedicine to energy conversion.
在过去的几十年中，人们投入了大量的精力来合成具有特定性能的纳米结构材料，这些性能最终决定了它们的功能。在碳纳米技术时代，对于富勒烯、碳纳米管和石墨烯等纳米材料，主要的关注点是对这些纳米结构进行有机功能化，以调整它们的可加工性和适用性。碳点，即尺寸小于 10nm 的准球形纳米粒子，由于其多功能的合成方法和有趣的性质（主要是荧光发射），特别是在这种背景下崭露头角。尽管它们是通过自上而下的方法从大的碳纳米结构中切割出来的，但近年来，自下而上的合成的简便性和灵活性使得这种碳基纳米材料以惊人的速度发展。然而，研究和出版的快速速度导致了一些影响它们的分类、纯度标准和荧光机制的问题。随着这些问题的逐步解决，这种纳米材料的真正潜力和适用性开始显现出来。在本文中，我们描述了我们在碳纳米点的合成、纯化、表征和应用方面的努力。特别关注的是设计和定制这些纳米材料的光电特性，以及它们在混合和复合材料系统中的应用。我们的方法以自下而上的微波辅助水热合成为中心。我们成功地利用了一种多组分合成方法，使用精氨酸和乙二胺作为起始材料。通过控制反应条件，仅在 3 分钟内就可以获得蓝色发射的碳纳米点。我们通过设计和调整这些纳米形式的发光、电化学和手性光学性质，改进了这种方法。另一方面，我们使用后功能化反应作为与合适的配体进行共轭的工具，并进一步调整表面化学。这两种方法的结合产生了许多可以在从生物学到材料化学的各个领域以及从纳米医学到能量转换的应用中进行研究的碳纳米点。
