Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Uttarakhand, India.
J Mater Chem B. 2020 Apr 21;8(15):3028-3037. doi: 10.1039/c9tb02823d. Epub 2020 Mar 18.
The excessive use of traditional antibiotic and antibacterial agents has globally increased the growth of antibiotic-resistant bacteria that poses serious health risks. Therefore, the development of new generation antibacterial or antimicrobial agents for effective inhibition of bacterial growth is highly desired. In this study, we report a facile one-step synthesis approach for the preparation of a nanocomposite composed of silver nanoparticles (AgNPs) decorated with sulfur-doped graphene quantum dots (S-GQDs). The nanocomposite was comprehensively characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis absorption spectra, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The characterization results demonstrated that the AgNPs were closely and uniformly surrounded by the S-GQDs, and consequently, this ensured the dispersion and stability of the so formed nanocomposite (Ag@S-GQDs). Further, the antibacterial activity of the Ag@S-GQDs nanocomposite was investigated and compared with bare S-GQDs and AgNPs against Gram-positive S. aureus (MTCC 737) and Gram-negative P. aeruginosa (MTCC 424) bacteria using macrodilution and agar well diffusion methods. Minimum inhibitory concentration (MIC) values of 70 and 35 μg mL of the Ag@S-GQDs nanocomposite were found to be sufficient to hinder the growth of P. aeruginosa and S. aureus. A fractional inhibition concentration (FIC) index below 0.5 confirmed the existence of a synergistic effect between AgNPs and S-GQDs in the Ag@S-GQDs nanocomposite. In addition, the cytotoxicity of the Ag@S-GQDs nanocomposite, AgNPs and S-GQDs was also investigated using HEK 293 cell lines. Interestingly, the Ag@S-GQDs nanocomposite exhibited superior cell viability as compared to AgNPs and S-GQDs. These improved antibacterial and biocompatibility data demonstrate that the Ag@S-GQDs nanocomposite can serve as a promising antibacterial agent for industry to fabricate next-generation self-sterile textiles, antibacterial coatings and useful health care products supporting cell viability.
过度使用传统的抗生素和抗菌剂已经在全球范围内导致了抗生素耐药菌的生长增加，从而对健康构成了严重威胁。因此，开发新一代的抗菌或抗微生物剂来有效抑制细菌生长是非常需要的。在这项研究中，我们报告了一种简便的一步合成方法，用于制备由银纳米颗粒（AgNPs）修饰的硫掺杂石墨烯量子点（S-GQDs）组成的纳米复合材料。通过透射电子显微镜（TEM）、X 射线衍射（XRD）、紫外-可见吸收光谱、傅里叶变换红外（FTIR）光谱和 X 射线光电子能谱（XPS）对纳米复合材料进行了全面的表征。表征结果表明，AgNPs 被 S-GQDs 紧密均匀地包围，从而确保了如此形成的纳米复合材料（Ag@S-GQDs）的分散性和稳定性。此外，还研究了 Ag@S-GQDs 纳米复合材料的抗菌活性，并通过大稀释法和琼脂孔扩散法将其与裸 S-GQDs 和 AgNPs 对革兰氏阳性的金黄色葡萄球菌（MTCC 737）和革兰氏阴性的铜绿假单胞菌（MTCC 424）进行了比较。发现 Ag@S-GQDs 纳米复合材料的最小抑菌浓度（MIC）值为 70 和 35 μg mL，足以阻止铜绿假单胞菌和金黄色葡萄球菌的生长。分数抑制浓度（FIC）指数低于 0.5 证实了 Ag@S-GQDs 纳米复合材料中 AgNPs 和 S-GQDs 之间存在协同作用。此外，还通过 HEK 293 细胞系研究了 Ag@S-GQDs 纳米复合材料、AgNPs 和 S-GQDs 的细胞毒性。有趣的是，与 AgNPs 和 S-GQDs 相比，Ag@S-GQDs 纳米复合材料表现出更高的细胞活力。这些改进的抗菌和生物相容性数据表明，Ag@S-GQDs 纳米复合材料可以作为一种有前途的抗菌剂，用于工业制造下一代自消毒纺织品、抗菌涂料和支持细胞活力的有用保健产品。
