Jin Jing, Zhu Shoujun, Song Yubin, Zhao Hongyue, Zhang Zhen, Guo Yue, Li Junbo, Song Wei, Yang Bai, Zhao Bing
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Alan G. MacDiarmid Institute, College of Chemistry, Jilin University , Changchun, 130012, P. R. China.
ACS Appl Mater Interfaces. 2016 Oct 19;8(41):27956-27965. doi: 10.1021/acsami.6b07807. Epub 2016 Oct 10.
Carbon dots (CDs) have attracted extensive interest owing to their unparalleled physical and chemical characteristics. CDs based nanocomposites have also drawn increasing attention because the combination of different characteristics could offer additional brilliant properties (such as photocatalysis and Raman scattering). In this work, we developed a fast, facile, and controllable method for fabricating core-shell Ag@CDs nanoparticles (NPs) based on the ability of CDs to directly reduce Ag to Ag NPs without an external photoirradiation process or additional reductants. The as-prepared Ag@CDs NPs caused efficient CDs fluorescence quenching, and the typical bands of carbon species were obtained in the Raman spectrum of CDs. In addition, we found that the Ag@CDs NPs could be utilized as an efficient surface-enhanced Raman scattering (SERS) substrate, showing a discernible detection concentration as low as 10 M by using p-aminothiophenol (PATP) as the probe molecules. The as-prepared Ag@CDs NPs used as the SERS substrate also exhibited excellent peroxidase-like catalytic activity for in situ super-sensitive monitoring of the oxidation of 3,3',5,5'-tetramethylbenzidine by HO, a plasmon-enhanced driven photocatalytic reaction of p-nitrothiophenol (PNTP) dimerizing into 4,4'-dimercaptoazobenzene, and catalytic driven reduction of PNTP to PATP in the presence of NaBH in real time. Moreover, the determination of HO with a significantly lower discernible detection concentration was obtained. This work demonstrated that the hybrid nanostructures not only exhibited unique SERS properties but also showed excellent catalytic activities, especially as an ultrasensitive SERS substrate for monitoring heterogeneous catalytic reactions in real time. This would make it possible to not only obtain the information about catalytic molecular changes but also conduct quantitative and qualitative analysis, and widen the application of CDs in SERS and catalytic reactions.
碳点（CDs）因其无与伦比的物理和化学特性而引起了广泛关注。基于碳点的纳米复合材料也越来越受到关注，因为不同特性的结合可以提供额外的优异性能（如光催化和拉曼散射）。在这项工作中，我们基于碳点在无外部光照射过程或额外还原剂的情况下直接将银还原为银纳米颗粒的能力，开发了一种快速、简便且可控的方法来制备核壳结构的Ag@CDs纳米颗粒（NPs）。所制备的Ag@CDs NPs导致碳点荧光有效猝灭，并且在碳点的拉曼光谱中获得了典型的碳物种谱带。此外，我们发现Ag@CDs NPs可作为一种高效的表面增强拉曼散射（SERS）基底，以对氨基硫酚（PATP）作为探针分子时，其可检测到低至10 M的可分辨浓度。所制备的用作SERS基底的Ag@CDs NPs还表现出优异的过氧化物酶样催化活性，可用于原位超灵敏监测HO对3,3',5,5'-四甲基联苯胺的氧化、对硝基硫酚（PNTP）在等离子体增强驱动下光催化二聚形成4,4'-二巯基偶氮苯，以及在NaBH存在下催化驱动PNTP还原为PATP。此外，还实现了对HO的测定，其可分辨检测浓度显著更低。这项工作表明，这种杂化纳米结构不仅表现出独特的SERS特性，还具有优异的催化活性，特别是作为一种超灵敏的SERS基底用于实时监测多相催化反应。这不仅使得获取催化分子变化的信息成为可能，还能够进行定量和定性分析，并拓宽了碳点在SERS和催化反应中的应用。
