本研究旨在制备、表征并研究壳聚糖-氧化钴（II）混合纳米复合材料对多种微生物的生物效力。我们利用傅里叶红外光谱（FTIR）、扫描电子显微镜（SEM）、X射线衍射（XRD）和能量色散X射线（EDX）等分析方法对所制备的壳聚糖-氧化钴（CS-CoO）纳米复合材料进行了深入表征。在傅里叶红外光谱中，681和558 cm-1处壳聚糖峰的存在以及CoO的峰的存在表明，CoO分子与壳聚糖骨架发生相互作用。此外，在X射线衍射测量中，观察到明显较低的壳聚糖结晶度，这是由于聚合物基质中溶解了更多的氧化钴。通过应用德拜-谢尔勒计算，发现所得纳米复合材料的结晶粒径从48.24 nm（重量为5%）减小到19.27 nm（重量为20%）。此外，通过扫描电子显微镜测量，观察到壳聚糖表面发生了变化，CoO分子物理吸附在壳聚糖表面活性位点上，清晰可见于SEM图中。此外，通过EDX测量确定了壳聚糖中Co元素的含量，其中20%重量的样品中发现了19.26%重量的Co元素。采用可变剂量平板扩散法评估了CS-Co纳米复合材料对广谱细菌和真菌的效力。与单独的壳聚糖相比，CS-CoO纳米复合材料在抗菌剂中对革兰阳性和革兰阴性细菌的效果更好。此外，采用MTT方法在不同的UV照射下测量细胞存活率，评估了CS-CoO纳米复合材料的细胞毒性。由于CS-CoO纳米复合材料能够轻松扩散到癌细胞中，所以在没有UV辐射的情况下具有抗癌活性。UV照射刺激了抗癌活性，这是由于壳聚糖及其CS-CoO纳米复合材料剂量的增加导致了ROS产生的增加。此外，通过DPPH自由基清除法验证了所制备的纳米复合薄膜的抗氧化活性，与标准维生素C相比，所制备的纳米复合材料表现出与DPPH自由基的良好清除性。而且，我们注意到，通过将CoO纳米颗粒含量从5%重量增加到20%重量，所制备的纳米复合材料的生物活性得到了增强。Copyright © 2023. Published by Elsevier B.V.

This research aimed to prepare, characterize, and investigate the biological efficacy of chitosan‑cobalt (II) oxide hybrid nanocomposites against a variety of micrograms. Analytical methods, FTIR, SEM, XRD, and EDX, were utilized to thoroughly characterize the produced CS-CoO nanocomposite. In FTIR spectra, the presence of the chitosan peaks in addition to that of CoO at 681 and 558 cm-1 confirmed that CoO molecules interact with the chitosan backbone. Moreover, in the XRD measurements, significantly less chitosan crystallinity was observed. Due to the incorporation of a larger amount of cobalt oxide within the polymer matrix. Applying the Debye-Sherrer calculation, the crystallite size was obviously reduced from 48.24 nm (5 % wt.) to 19.27 nm (20 % wt.) for the obtained nanocomposites. Furthermore, SEM measurements showed a transformation in the chitosan surface with the physical adsorption of CoO molecules on the surface active sites of chitosan that were visible in SEM graphs. Additionally, EDX determined the amount of Co element within the chitosan, with the sample of 20 % weight being found to be 19.26 % weight. The variable dose well-diffusion method was utilized to assess the efficacy of the CS-Co nanocomposite against a wide range of bacteria and fungi. CS - CoO nanocomposite is more effective than chitosan alone as an antibacterial agent against both Gram-positive and Gram-negative bacteria. Moreover, the MTT approach was employed to measure the cytotoxicity based on the cell viability of different cancer cell lines under different UV expositions. The proportion of the destroyed cells elevated due to the easy diffusion of CS - CoO nanocomposite into cancer cells as UV-free anticancer activity. UV exposition has stimulated the anticancer activity, which was attributed to an increase in ROS generation caused by the increased dose of the chitosan and its CS - CoO nanocomposites. Furthermore, the antioxidant capacities of the prepared nano-composites thin films were validated using the DPPH free radical scavenging method and showed good antioxidant activities with the DPPH radical compared with standard vitamin C. It has been noticed that by increasing the content of CoO nanoparticles from 5 to 20 % wt., the biological activity of the prepared nanocomposites was enhanced.Copyright © 2023. Published by Elsevier B.V.