Aqueous dispersibility of graphene oxide (GO) sheets can be improved through enrichment of oxygen content (oxidation). However, the resulting ‘oxygen clusters’ are accompanied with numerous point defects, depletive to π-π stacking behavior of sheets. In this work, we have investigated the properties of sheets oxidized with 2, 4, 6, 8, 10 and 12 weight equivalents of KMnO₄. Sheets were characterized by spectroscopic, X-ray diffraction (XRD) and electron microscopic techniques. Paclitaxel (PLX) was used as a model drug to analyze the changes in the loading efficiency at different levels of oxidation.

Density of oxygen clusters increased as we shifted across increasing proportion of KMnO₄. This was accompanied with increased inter-layer spacing, disruption of pure graphitic domains and changes in hybridization of carbon atoms (sp² to sp³). However, these defects exhibited the tendency of saturation at a finite proportion of KMnO₄. Oxygen groups negatively affected the loading efficiency of sheets for PLX. Improvement in the loading efficiency of reduced GO (rGO) sheets clarified the predominant role of π-π interactions at the surface. Our study reveals that high oxidation may offset the loading potential of highly aqueous dispersible GO sheets. Therefore, the extent of oxidation must be tuned taking into account the availability of H-bond forming groups in the drug molecule.

可以通过富集氧含量（氧化）来改善氧化石墨烯（GO）片的水分散性。然而，所产生的“氧簇”伴随着许多点缺陷，这不利于片材的π-π堆积行为。在这项工作中，我们研究了被2、4、6、8、10和12重量当量的KMnO ₄氧化的片材的性能。通过光谱，X射线衍射（XRD）和电子显微镜技术对片材进行表征。紫杉醇（PLX）被用作模型药物，以分析不同氧化水平下负载效率的变化。

随着KMnO ₄比例的增加，氧簇的密度增加。这伴随着层间间距的增加，纯石墨结构域的破坏以及碳原子杂交的改变（sp ²至sp ³）。但是，这些缺陷在KMnO ₄的有限比例下表现出饱和趋势。。氧基团负面影响了PLX纸张的装载效率。减少的GO（rGO）薄板加载效率的提高阐明了表面π-π相互作用的主要作用。我们的研究表明，高氧化度可能会抵消高水分散性GO片材的加载潜力。因此，必须考虑到药物分子中氢键形成基团的可用性来调节氧化程度。