School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450004, China.
School of Biomedical Engineering and Medical Imaging, Army Medical University, Chongqing, 400038, China.
Chemistry. 2023 May 22;29(29):e202204071. doi: 10.1002/chem.202204071. Epub 2023 Apr 12.
Ceria nanoparticles (CNPs) are important typical nanozymes with multiple enzyme mimetic activities, which could facilitate the oxidation of organic dyes in acidic conditions, because of the oxidase mimetic activity. Usually, the regulation of oxidase mimetic activity is focused on the adjustment of the structure, morphology, composition, surface, and other factors of nanozymes. However, the influence of the surrounding environment is not considered, which is very important during the reaction process. In this work, the oxidase mimetic activity of CNPs in buffer solutions including citric acid, acetic acid and glycine buffer solutions was investigated, with the results that carboxyl group in buffer solution could adsorb the CNPs on the surface to promote the oxidase mimetic activity. Due to the chelation with the cerium ion, the enhancement is more significant by molecules with polycarboxylic groups, and the enhancement is more efficient by carboxyl molecules in buffer solution, compared with the modification of the carboxyl groups on the surface, because of easier operation and smaller steric hindrance. From the viewpoint of increasing the oxidase mimetic activity of CNPs, the work is expected to provide references for the selection of the reaction systems to optimize the oxidase mimetic activity in bio-detection applications.
铈纳米粒子（CNPs）是具有多种酶模拟活性的重要典型纳米酶，由于其氧化酶模拟活性，可促进酸性条件下有机染料的氧化。通常，氧化酶模拟活性的调节集中在纳米酶的结构、形态、组成、表面和其他因素的调整上。然而，在反应过程中，未考虑周围环境的影响，这一点非常重要。在这项工作中，研究了包括柠檬酸、乙酸和甘氨酸缓冲溶液在内的缓冲溶液中 CNPs 的氧化酶模拟活性，结果表明缓冲溶液中的羧基基团可以将 CNPs 吸附在表面上，从而促进氧化酶模拟活性。由于与铈离子的螯合作用，具有多羧基基团的分子的增强效果更为显著，并且与表面羧基基团的修饰相比，缓冲溶液中的羧基分子的增强效果更为高效，因为其操作更容易，空间位阻更小。从提高 CNPs 氧化酶模拟活性的角度来看，这项工作有望为选择反应体系提供参考，以优化生物检测应用中的氧化酶模拟活性。
