Studies On Au@PEG-ferulic Acid Antioxidant Properties And Sythesis Of Watersoluble Fluorescent Probe

Free radical production and scavenging is a dynamic equilibrium in vivo, Excessive production of free radicals can react with lipids,proteins and DNA, leading to several diseases, such as cardiopathy, cancer and caducity. Natural antioxidant ferulic acid can scavenge free radicals and remedy the diseases caused by free radicals. However, poor biocompatibility and low removal efficiency of ferulic acid limits its applications.Nanoparticles used with natural antioxidant can improve their antioxidant ability. Nie zhou synthesis Au@Trolox, its free radicals clearance rate is eight times as Trolox, but Au@Trolox has potential biological toxicity. To solv the problems, we adopt nanometer gold(4.5nm) as matrix, polyethylene glycol (PEG) was used in substitution for thiol ligand. The product Au@PEG-Ferulic acid represents excellent water-solubility. The radical scavenging ability and kinetic properties of Au@PEG-Ferulic acid had been compared with Ferulic acid by DPPH·scavenging efficiency. The results showed that Au@PEG-Ferulic acid has higher scavenging ability than Ferulic acid, the apparent activation energy (Ea) of Au@PEG-Ferulic acid much lower than the Ferulic acid. Mechanism of this phenomenon are attributed to the preconcentration of the reactants and the aromatic stacking of the phenol rings in adjacent Ferulic acid. MTT experiments were taken to determine the toxicology of Au@PEG-Ferulic acid. Au@PEG-Ferulic acid did not show any detectable cytotoxicity within certain concentration. Cell experiments shows Au@PEG-Ferulic could alleviate the oxidative damage caused by free radicals.Free radicals detection is a important indicator to evaluate efficacy of drugs and disease prevention. To detect free radicals, a new free radicals fluorescent probe (N-(phenylmethylene)benzenamine N-oxide,NPBN) was designed and synthesized in this work. Then we used Nano-graphene oxide (NGO) as carrier, obtained a kind of watersoluble probe NGO-NPBN. UV, IR, FL results confirmed that NPBN linked byπ-πstacking to the NGO. The ability of NGO-NPBN to capture hydroxyl radical and superoxide anion were determined by fluorescent quenching experiments.