Study on the preparation of novel flavonol-gold nanoparticles antioxidants and the mechanism of protein corona formation

Abstract

In this work, we reported the methodology involved in the binding of galangin/kaempferol/quercetin/myricetin onto the surface of 10.3 nm and 31.3 nm citrate-capped gold nanoparticles (AuNPs) by a simple in situ method to prepare the eight novel flavonol-AuNPs antioxidants. We systematically performed UV–vis spectroscopy, the hydrodynamic diameter, and zeta potential to characterize the novel flavonol-AuNPs antioxidants. The antioxidative effect of the novel flavonol-AuNPs antioxidants was determined using DPPH radical, hydroxyl radical and superoxide anion radical scavenging assays. The results indicate that the novel flavonol-AuNPs antioxidants scavenging ability of these three free radicals is significantly enhanced compared with flavonols or AuNPs. The scavenging capacity of 31.3 nm flavonol-AuNPs antioxidants is greater than that of 13.3 nm flavonol-AuNPs antioxidants. The free radical scavenging ability of quercetin/myricetin-AuNPs antioxidants is higher than that of galangin/kaempferol-AuNPs antioxidants. And then, the mechanism of protein corona formation between the eight novel AuNPs-flavonol antioxidants and γ-globulin/fibrinogen/trypsin/pepsin and the conformational changes of the four proteins caused by the protein corona formation were systematically and quantitatively investigated by various spectral techniques. Overall, we ascertain the fact that this kind of novel flavonol-AuNPs antioxidants will contribute to the development of safe and effective AuNPs antioxidants in biological systems.