在本研究中,我们探索了牛血清白蛋白（BSA）与氧化氧化石墨烯（GO）纳米片的相互作用。纳米片，用4、6、8、10和12wt当量的KMnO4作为氧化剂合成，分别编码为GO-4、GO-6、GO-8、GO-10和GO-12。在室温下用固定浓度的BSA孵育片材后，随着时间的推移监测相互作用。分析基于紫外可见光谱，荧光猝灭,动态光散射(DLS),小角度中子散射（SANS），傅里叶变换红外(FTIR)光谱和圆二色性(CD)技巧。以以下顺序记录BSA在片材上的结合:GO-04>>GO-06>GO-08>GO-10≈GO-12。我们的观察结果表明，这些相互作用在很大程度上受到纯石墨域的可用性和片材表面上氧官能团的密度的调节。这导致我们得出这样的结论:通过调节片层氧化的程度,可以使GO-蛋白质相互作用最小化。此外，我们表明，蛋白质作为胶体聚集体的吸附有助于改善片材的生物安全性。蛋白质分子的构象没有表现出破坏性的变化。然而,从药物递送应用的角度来看，必须优化氧基团的密度，以最大程度地提高氧化片的负载效率。
In the present study, we explored the interaction of bovine serum albumin (BSA) with oxidized graphene oxide (GO) nanosheets. Nanosheets, synthesized with 4, 6, 8, 10 and 12 wt equivalents of KMnO4 as oxidant, were coded as GO-4, GO-6, GO-8, GO-10 and GO-12, respectively. After incubating sheets with a fixed concentration of BSA at room temperature, interactions were monitored with time. The analysis is based on UV-vis spectroscopy, fluorescence quenching, dynamic light scattering (DLS), small angle neutron scattering (SANS), Fourier transform infrared (FTIR) spectroscopy and circular dichroism (CD) techniques. Binding of BSA over sheets was recorded in the following order; GO-04 >> GO-06 > GO-08 > GO-10 ≈ GO-12. Our observations suggest that these interactions are largely regulated by the availability of pure graphitic domains and density of oxygen functionalities on sheet surface. This led us to the conclusion that GO-protein interactions can be minimized by modulating the extent of sheet oxidation. Moreover, we show that adsorption of proteins as colloidal aggregates contributes to improved biosafety of sheets. The protein molecule did not exhibit depletive changes in its conformation. However, from the viewpoint of drug delivery applications, density of oxygen groups must be optimized for maximizing the loading efficiency of oxidized sheets.
