Sun Yisheng, Li Qianwei, Du Xiangwei, Thipe Velaphi, Vardhanabhuti Bongkosh, Sengupta Shramik, Katti Kattesh, Wan Caixia
Department of Biomedical, Biological, and Chemical Engineering, University of Missouri, Columbia, Missouri 65211, United States.
Veterinary Medical Diagnostic Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, Missouri 65211, United States.
ACS Omega. 2022 Oct 31;7(45):41548-41558. doi: 10.1021/acsomega.2c05400. eCollection 2022 Nov 15.
Lignin-containing nanocelluloses (LNCs) have the properties of both lignin and nanocellulose and could overcome the limits of both individual components in metallic nanoparticle synthesis. However, studies on LNCs are still limited, and the potential of such nanomaterials for metallic nanoparticle synthesis has not been fully unraveled. In this study, monometallic silver, gold nanoparticles, and Ag-Au-AgCl nanohybrids were synthesized in situ utilizing LNCs in a chemical-free approach. The parameters, including Ag and Au concentrations as well as [Au]/[Ag] ratios, were investigated for their effects on the nanoparticle synthesis. The characterizations, including UV-vis spectrophotometry, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), confirmed the coexistence of Ag, Au, and AgCl while indicating the key role of lignin and oxygen-containing functional groups in the nanoparticle synthesis. The as-synthesized AgNPs-, AuNPs-, and nanohybrids-LNC samples were tested for their antibacterial activities. In comparison to the monometallic AgNPs-LNC sample, nanohybrids-LNC synthesized with 0.063 mM Au loading showed superior antibacterial activities with minimum inhibitory concentrations (MICs) at 5 μg/mL against Gram-positive and 10 μg/mL against Gram-negative with controlled Ag release. The results indicated that LNCs can be used to synthesize metallic nanoparticles, and the resultant Ag-Au-AgCl nanohybrids were a potent antibacterial agent with reduced environmental impacts.
含木质素的纳米纤维素（LNCs）兼具木质素和纳米纤维素的特性，在金属纳米颗粒合成中能够克服这两种单一成分的局限性。然而，关于LNCs的研究仍然有限，这类纳米材料在金属纳米颗粒合成方面的潜力尚未得到充分发掘。在本研究中，采用无化学添加方法，利用LNCs原位合成了单金属银、金纳米颗粒以及Ag-Au-AgCl纳米杂化物。研究了银和金的浓度以及[Au]/[Ag]比例等参数对纳米颗粒合成的影响。通过紫外可见分光光度法、透射电子显微镜（TEM）、X射线光电子能谱（XPS）、X射线粉末衍射（XRD）和傅里叶变换红外光谱（FTIR）等表征手段，证实了Ag、Au和AgCl的共存，同时表明了木质素和含氧官能团在纳米颗粒合成中的关键作用。对合成的AgNPs-、AuNPs-和纳米杂化物-LNC样品进行了抗菌活性测试。与单金属AgNPs-LNC样品相比，负载0.063 mM Au合成的纳米杂化物-LNC具有优异的抗菌活性，对革兰氏阳性菌的最低抑菌浓度（MIC）为5 μg/mL，对革兰氏阴性菌为10 μg/mL，且银释放可控。结果表明，LNCs可用于合成金属纳米颗粒，所得的Ag-Au-AgCl纳米杂化物是一种强效抗菌剂，对环境的影响较小。
