PEG修饰Fe_3O_4纳米粒子(MNPs)的制备及催化氧化VB_1研究

Studies on catalytic oxidation of VB_1 by PEG modified Fe_3O_4 nanoparticles

维生素B_1(VB_1)对人体正常生理功能起着重要作用,缺乏VB_1会导致人体出现多种疾病。某些温和的氧化剂可将VB_1氧化为含有荧光的硫色素,硫色素在紫外光照射下发出荧光,其荧光强度与VB_1浓度成正比。本文首先制备Fe_3O_4纳米粒子(MNPs),通过优化实验条件,制备Fe_3O_4@SiO_2、Fe_3O_4@SiO_2-NH_2纳米粒子,对Fe_3O_4@SiO_2-NH_2样品进行双端羧基PEG修饰,得到Fe_3O_4@SiO_2-NH_2-PEG-COOH样品,设置3种不同的试验条件,利用PEG修饰产物催化VB_1为有荧光的硫色素,再经荧光分光光度计检测。研究结果表明,PEG修饰的Fe_3O_4 MNPs在不同H_2O_2浓度、不同温度及不同纳米粒子浓度时均可催化VB_1反应,产生荧光硫色素,但效果均不明显,而Fe_3O_4对温度和纳米粒子浓度的反应较大。

VB1 plays an important role in the normal life of human body. Relevant literature suggest that VB1 could be oxidized to sulfur containing fluorescent pigment by some mild oxidant. Sulfur fluorescent dyes could fluoresced under UV irradiation, and the fluorescence intensity is proportional to the concentration of VB1. In this study, Fe3O4, Fe3O4@SiO2 and Fe3O4@ SiO2-NH2 MNPs were prepared. Fe3O4@SiO2-NH2-PEG-COOH MNPs could be prepared by Fe3O4@SiO2-NH2 MNPs via PEG modification. Under three different test conditions, VB1 could be oxidized by Fe3O4@SiO2-NH2-PEG-COOH MNPs, and the obtained sulfur fluorescent dyes could be detected by fluorescence spectrophotometer. The results showed that VB1 could be catalyzed by the PEG modified Fe3O4 MNPs in different H2O2 concentration, different temperatures and different concentration of nanoparticles and produce fluorescent sulfur pigment, but the effect is not obvious. As for Fe3O4, response to temperature and concentration of nanoparticles is big.