State Key Laboratory of Rare Earth Resources Utilization and Laboratory of Chemical Biology , Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022 , P. R. China.
University of Science and Technology of China , Hefei 230029 , P. R. China.
Nano Lett. 2018 Jun 13;18(6):3344-3351. doi: 10.1021/acs.nanolett.7b05095. Epub 2018 May 17.
Carbon nanotubes (CNTs) and their derivatives have emerged as a series of efficient biocatalysts to mimic the function of natural enzymes in recent years. However, the unsatisfiable enzymatic efficiency usually limits their practical usage ranging from materials science to biotechnology. Here, for the first time, we present the synthesis of several oxygenated-group-enriched carbon nanotubes (o-CNTs) via a facile but green approach, as well as their usage as high-performance peroxidase mimics for biocatalytic reaction. Exhaustive characterizations of the enzymatic activity of o-CNTs have been provided by exploring the accurate effect of various oxygenated groups on their surface including carbonyl, carboxyl, and hydroxyl groups. Because of the "competitive inhibition" effect among all of these oxygenated groups, the catalytic efficiency of o-CNTs is significantly enhanced by weakening the presence of noncatalytic sites. Furthermore, the admirable enzymatic activity of these o-CNTs has been successfully applied in the treatment of bacterial infections, and the results of both in vitro and in vivo nanozyme-mediated bacterial clearance clearly demonstrate the feasibility of o-CNTs as robust peroxidase mimics to effectively decrease the bacterial viability under physiological conditions. We believe that the present study will not only facilitate the construction of novel efficient nanozymes by rationally adjusting the degree of the "competitive inhibition" effect, but also broaden the biological usage of o-CNT-based nanomaterials via their satisfactory enzymatic activity.
近年来，碳纳米管（CNTs）及其衍生物作为一系列高效的生物催化剂，已经开始模拟天然酶的功能。然而，不尽如人意的酶效率通常限制了它们从材料科学到生物技术的实际应用。在这里，我们首次通过一种简单但绿色的方法合成了几种含氧基团丰富的碳纳米管（o-CNTs），并将其用作生物催化反应的高性能过氧化物酶模拟物。通过探索表面上各种含氧基团（包括羰基、羧基和羟基）对其酶活性的精确影响，对 o-CNTs 的酶活性进行了详尽的表征。由于所有这些含氧基团之间的“竞争抑制”效应，通过削弱非催化位点的存在，o-CNTs 的催化效率得到显著提高。此外，这些 o-CNTs 的令人钦佩的酶活性已成功应用于细菌感染的治疗，体外和体内纳米酶介导的细菌清除的结果清楚地表明，o-CNTs 作为强大的过氧化物酶模拟物具有可行性，可在生理条件下有效降低细菌的存活率。我们相信，本研究不仅将通过合理调整“竞争抑制”效应的程度来促进新型高效纳米酶的构建，而且还将通过其令人满意的酶活性拓宽基于 o-CNT 的纳米材料的生物学用途。
