Abstract To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO2 spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO2/Ag NPs composites were obtained in situ under UV light irradiating by using mesoporous SiO2 and Ag NO3 as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO2/Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO2/Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureus and Escherichia coli via disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO2/CQDs and mesoporous SiO2/Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO2/Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.

中文翻译：

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通过原位合成的 CQDs/介孔 SiO2/Ag NPs 复合材料的光学和抗菌性能的变化和改进

摘要 为了改变碳量子点（CQDs）和Ag NPs的光学性质并提高其抗菌性能，将介孔SiO2球与它们结合形成复合材料。在本文中，使用葡萄糖作为碳源合成了尺寸均匀约为 3.74 nm 的 CQD。然后，分别以介孔SiO2和Ag NO3为载体和银资源，在紫外光照射下原位获得CQDs/介孔SiO2/Ag NPs复合材料。CQDs/介孔 SiO2/Ag NPs 颗粒的直径在 200-250 nm 范围内。随着辐照时间的增加，所制备的CQDs/介孔SiO2/Ag NPs复合材料的紫外-可见光谱出现红移，吸附峰变宽。此外，该复合材料通过圆盘扩散法对金黄色葡萄球菌和大肠杆菌表现出较高的抗菌活性。这些结果表明，Ag NPs/介孔 SiO2/CQDs 和介孔 SiO2/Ag NPs 的抑制环直径相似。此外，与其他颗粒相比，这两种复合材料具有更好的杀菌性能。因此，本文所制备的CQDs/介孔SiO2/Ag NPs复合材料在荧光材料和抗菌材料方面具有巨大的应用潜力。