基于柠檬酸的石墨烯量子点的制备及其应用

石墨烯量子点（GQDs）是一种新型碳基准零维材料，不但具有石墨烯的独特平面结构，同时具备碳点的量子限制效应和边界效应。GQDs具有独特的光学性质、低毒性、高荧光稳定性和高生物相容性，被广泛应用于检测、传感、催化、细胞成像、药物递送和污染治理等领域。GQDs的合成分为自上而下法和自下而上法，前者将大尺寸的石墨烯、石墨、碳材料切割成纳米级的量子点，后者使用不同的前驱体，通过水热法、热裂解法等方法合成石墨烯量子点。柠檬酸（CA）是一种重要的有机酸，室温下是白色结晶状粉末，是自下而上法合成GQDs的一种常用前驱体，近年来有许多关于以CA为前驱体合成不同GQDs的研究，以CA为前驱体合成的GQDs（CA-GQDs）在生物医药、荧光检测、成像等领域均有应用，具有较好的应用前景。对近年来基于CA的合成方法和具体应用进行了总结和回顾，旨在将现有CA-GQDs的相关成果尽可能汇总和展现，以对相关领域研究工作者提供一定参考，并对未来CA-GQDs较有前景的研究方向进行了展望。

Synthesis and Applications of Graphene Quantum Dots Derived from Citric Acid

Graphene quantum dots （GODs） are a kind of novel carbon-based zero-dimensional materials， which can be regarded as extremely small graphene fragments. GQDs possess unique 2D structure， quantum confinement effect and edge effect， which is similar to graphene materials. GQDs have many advantages， such as unique photoluminescence property， low toxicity， high fluorescent stability and high biocompatibility， which result in extensive applications of GQDs， including detection， sensing， catalysis， cellular-imaging， drug delivery and pollution control. The synthesis methods of GQDs could be divided into top-down and bottom-up. The mechanism of the top-down method is cutting large-size materials like graphene， graphite and carbon materials into smaller sizes to obtain GQDs， while the mechanism of the bottom-up method is synthesizing GQDs using different precursors through the hydrothermal method or pyrolysis. Citric acid （CA） is a kind of the most popular precursors used in synthesis of GQDs through the bottom-up method. In the recent years， lots of research related to synthesis of GQDs by using CA as precursors are published. In this study， many CA-based synthesis methods of heterogeneous GQDs and their applications are introduced.