Han Lei, Zeng Lingxing, Wei Mingdeng, Li Chang Ming, Liu Aihua
Laboratory for Biosensing, Key Laboratory of Biofuels, and Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy & Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China.
Nanoscale. 2015 Jul 21;7(27):11678-85. doi: 10.1039/c5nr02694f. Epub 2015 Jun 22.
It is of great scientific and practical significance to explore inorganic mimetic enzymes to replace natural enzymes due to their instability and high cost. Herein we present an interesting discovery that a V2O3-ordered mesoporous carbon composite (V2O3-OMC) has a novel peroxidase-like activity towards fast redox reaction of typical peroxidase substrates H2O2 and 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS). Due to the small size effect and large surface area of V2O3 nanoparticles supported by OMC, V2O3-OMC exhibited excellent catalytic performance with a k(cat) of 1.28 × 10(4) s(-1), K(M) (ABTS) of 0.067 mM and K(M) (H2O2) of 0.16 mM, and a significantly higher catalytic efficiency (k(cat)/K(M)) towards the oxidation of ABTS in comparison with the natural peroxidases. Furthermore, the Ping-pong BiBi mechanism was proposed to explain the catalytic reaction by V2O3-OMC. Based on this highly active biomimetic peroxidase and the colorimetric detection of H2O2, a facile analytical method was developed to detect glucose by using V2O3-OMC and glucose oxidase, which had a wide linear range (0.01-4 mM glucose), good selectivity and reliability for successful detection of various real samples. Thus, the novel V2O3-OMC peroxidase mimetic holds great promise for broad potential applications.
由于天然酶的不稳定性和高成本，探索无机模拟酶来替代天然酶具有重大的科学和实际意义。在此，我们展示了一个有趣的发现，即V2O3有序介孔碳复合材料（V2O3-OMC）对典型过氧化物酶底物H2O2和2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）的快速氧化还原反应具有新型过氧化物酶样活性。由于OMC负载的V2O3纳米颗粒的小尺寸效应和大表面积，V2O3-OMC表现出优异的催化性能，其催化常数k(cat)为1.28×10(4) s(-1)，对ABTS的米氏常数K(M)（ABTS）为0.067 mM，对H2O2的米氏常数K(M)（H2O2）为0.16 mM，并且与天然过氧化物酶相比，对ABTS氧化的催化效率（k(cat)/K(M)）显著更高。此外，还提出了乒乓双底物机制来解释V2O3-OMC的催化反应。基于这种高活性的仿生过氧化物酶以及H2O2的比色检测，开发了一种简便的分析方法，使用V2O3-OMC和葡萄糖氧化酶来检测葡萄糖，该方法具有宽线性范围（0.01 - 4 mM葡萄糖），对各种实际样品的成功检测具有良好的选择性和可靠性。因此，新型V2O3-OMC过氧化物酶模拟物具有广阔的潜在应用前景。
