Abstract

Developing nanomaterial-based enzyme mimics for DNA cleavage is an interesting challenge and it has many potential applications. Single-layered graphene oxide (GO) is an excellent platform for DNA adsorption. In addition, GO has been employed for photosensitized generation of reactive oxygen species (ROS). Herein, we demonstrate that GO sheets could cleave DNA as a nuclease mimicking nanozyme in the presence of UV or blue light. For various DNA sequences and lengths, well-defined product bands were observed along with photobleaching of the fluorophore label on the DNA. Different from previously reported GO cleavage of DNA, our method did not require metal ions such as Cu²⁺. Fluorescence spectroscopy suggested a high adsorption affinity between GO and DNA. For comparison, although zero-dimensional fluorescent carbon dots (C-dots) had higher photosensitivity in terms of producing ROS, their cleavage activity was much lower and only smeared cleavage products were observed, indicating that the ROS acted on the DNA in solution. Based on the results, GO behaved like a classic heterogeneous catalyst following substrate adsorption, reaction, and product desorption steps. This simple strategy may help in the design of new nanozymes by introducing light.

中文翻译：

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氧化石墨烯作为模仿纳米酶的光催化核酸酶，用于DNA切割

摘要

开发基于纳米材料的酶模拟物以进行DNA切割是一个有趣的挑战，它具有许多潜在的应用。单层氧化石墨烯（GO）是DNA吸附的绝佳平台。另外，GO已被用于光敏生成活性氧（ROS）。在本文中，我们证明了GO片材可以在存在紫外线或蓝光的情况下将DNA切割为模拟纳米酶的核酸酶。对于各种DNA序列和长度，观察到明确定义的产物带以及DNA上荧光团标记的光漂白。与以前报道的GO裂解DNA不同，我们的方法不需要金属离子，例如Cu ²⁺。荧光光谱表明GO和DNA之间具有高吸附亲和力。为了进行比较，尽管就产生ROS而言，零维荧光碳点（C-点）具有更高的光敏性，但是它们的裂解活性要低得多，并且仅观察到涂抹的裂解产物，表明ROS作用于溶液中的DNA。根据结果​​，在底物吸附，反应和产物解吸步骤之后，GO表现得像经典的多相催化剂。这种简单的策略可以通过引入光来帮助设计新的纳米酶。