基于γ-Fe_(2)O_(3)磁性纳米微球的过氧化物模拟酶研究

Studies on peroxidase mimics based on γ-Fe_(2)O_(3) magnetic nanoparticles

研究以γ-Fe_(2)O_(3)为基础的磁性纳米微球通过化学修饰是否可以具有过氧化物模拟酶的催化性质,通过制备SiO_(2)包被的γ-Fe_(2)O_(3)磁性纳米粒子,采用共价修饰方法对γ-Fe_(2)O_(3)@SiO_(2)磁性纳米粒子用葡萄糖氧化酶(GOD)修饰后得到γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH-GOD磁性纳米微球,通过红外吸收光谱(IR)对γ-Fe_(2)O_(3)、γ-Fe_(2)O_(3)@SiO_(2)、γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)、γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH和γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH-GOD磁性纳米微球进行结构确证。结果表明,磁性纳米微球的氨基化、羧基化及GOD修饰成功。利用荧光分光光度计测定后,证明γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH-GOD具有过氧化物模拟酶的催化性质,可以催化H_(2)O_(2)和TMB之间的反应,葡萄糖的分解浓度过高酶也会出现淬灭现象。

This article intends to study whetherγ-Fe_(2)O_(3)-based magnetic nanoparticles can have the catalytic properties of peroxidase mimics by chemical modification.By preparing SiO_(2)-coatedγ-Fe_(2)O_(3) magnetic nanoparticles,and then adopting covalent modification methods,γ-Fe_(2)O_(3)@SiO_(2) magnetic nanoparticles were modified with glucose oxidase(GOD),γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH-GOD magnetic nanoparticles were obtained,and thenγ-Fe_(2)O_(3),γ-Fe_(2)O_(3)@SiO_(2),γ-Fe_(2)O_(3)@SiO_(2)-NH_(2),γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH andγ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH-GOD magnetic nanoparticles were used for structural confirmation.The results showed that the amination,carboxylation and GOD-modification of the magnetic nanoparticles were successful.After measuring with a fluorescence spectrophotometer,γ-Fe_(2)O_(3)@SiO_(2)-NH_(2)-COOH-GOD was proved to have the catalytic properties of a peroxidase mimicking enzyme,which can catalyze the reaction between H_(2)O_(2) and TMB.However,if the glucose decomposition concentration is too high,the enzyme quenching will also occur.