该研究以正硅酸乙酯为硅源，用改良的Stöber法制备了多孔二氧化硅微球，并用3-氨丙基乙氧基硅对其进行氨基功能化，成功将其与槲皮素复合，制备了多孔硅/槲皮素复合纳米材料。研究表明，多孔二氧化硅微球的比表面积、比孔容和平均孔径分别为1530.63 m2/g、0.92 cm3/g和2.40 nm。对比实验证明每毫克氨基功能化的二氧化硅微球能够负载0.09 mg槲皮素，是功能化之前的2.25倍。原因有两个，一是因为氨基是亲水性基团，氨基化的二氧化硅微球具有更好的水分散性；另一方面，氨基可与槲皮素分子中的羟基形成氢键，使得氨基化的二氧化硅微球更容易与槲皮素复合。用DPPH法表征了该复合纳米材料的自由基清除率。结果表明，在相同条件下，多孔硅/槲皮素复合纳米材料和纯槲皮素的自由基清除率分别为48.44%和32.81%，这说明与多孔二氧化硅微球复合可以提高槲皮素的抗氧化活性，可能与多孔二氧化硅微球对槲皮素的保护作用有关。

Quercetin, as a kind of flavonol compound, has been applied in the fields of food and medicine, because of its attracting physiological functions and pharmacological activities such as anti-oxidation, anti-tumor, lipid-lowering and anti-bacteria. Porous silica is a new type of carrier material and it has many advantages including large specific surface area, good compatibility, ordered and controllable pore channels. More importantly, it is easy to be modified. In this paper, porous silica microspheres were prepared by modified Stöber method, and they were functionalized by introducing amino groups. Based on this, porous silica/quercetin composite materials were synthesized successfully. The prepared porous silica spheres exhibited high specific area (153.63 m2/g) and uniform distribution of pore size (2.40 nm). The control experiments displayed that 0.09 mg quercetin could be loaded per milligram amino-functionalized silica spheres, which was 2.25 times that of the pre-functionalized silica sphere. The possible reason is that amino groups are hydrophilic, so the water dispersion of silica spheres becomes better after introducingamino groups. On the other hand, hydrogen bonds can form easily between amino and hydroxyl groups, so that amino groups functionalized silica spheres can be composite withquercetin easily. The free radical removing activities of the hybrid materials were characterized by DPPH method. The results showed the free radical removing activities of porous silica/quercetin composite materials and pure quercetin were 48.44% and 32.81% under the same condition, respectively. This indicates that the antioxidant activities of composite materials were higher than that of pure quercetin, which may be related to the protective effect of porous silica microspheres on quercetin.

河南省高等学校重点科研项目（20A150042）；郑州工程技术学院2020年校级大学生创新创业训练计划项目（202011068031）