Wrinkles have been frequently observed in a graphene nanosheet. Such structural corrugations can influence graphene’s characteristics and have received considerable attention recently. However, the impact of these wrinkles on the critical graphene interactions with biomolecules remains unclear. Here, we investigate the interaction of a double-stranded DNA (dsDNA) segment with a wrinkled graphene nanosheet using molecular dynamics simulations. We find that dsDNA experiences severe structural deformation upon binding to a wrinkled graphene surface, whereas it tends to maintain its native structure upon binding to an idealized graphene nanosheet. Further analysis reveals that it is energetically advantageous for the terminal bases to bind to the wrinkled area, serving as anchors on the nanosheet. Consequently, movement of the remaining part of the dsDNA generates a “centripetal stretching” force to the anchoring bases, causing the breakage of the interbase hydrogen bonds and local unfolding. Like a slider opening up a zipper, the local unfolding proceeds sequentially from the first base pair to the next until the end. This zipper-like unfolding subsequently exposes more DNA bases to contact with the wrinkled area, thus accelerating the dsDNA deformation. These findings highlight the importance of wrinkles in the interaction of graphene with biomolecules and deepen our understanding of graphene nanotoxicity in general.

中文翻译：

---

石墨烯皱纹导致dsDNA的拉链状展开

在石墨烯纳米片中经常观察到皱纹。这样的结构波纹会影响石墨烯的特性，并且最近受到了相当大的关注。然而，这些皱纹对临界石墨烯与生物分子相互作用的影响尚不清楚。在这里，我们使用分子动力学模拟研究双链DNA（dsDNA）段与起皱的石墨烯纳米片的相互作用。我们发现，dsDNA在结合到起皱的石墨烯表面时会经历严重的结构变形，而在结合到理想化的石墨烯纳米片时，它倾向于保持其天然结构。进一步的分析表明，末端碱基与起皱的区域结合并在纳米片上起锚作用在能量上是有利的。所以，dsDNA其余部分的移动会向锚定碱基产生“向心拉伸”力，从而导致碱基间氢键断裂和局部解折叠。就像拉开拉链的拉头一样，局部展开从第一个碱基对到下一个碱基对依次进行，直到结束。这种类似拉链的展开随后暴露出更多的DNA碱基与皱纹区域接触，从而加速了dsDNA的变形。这些发现突出了皱纹在石墨烯与生物分子相互作用中的重要性，并加深了我们对石墨烯纳米毒性的一般理解。局部展开从第一个碱基对到下一个碱基对依次进行，直到末端。这种类似拉链的展开随后暴露出更多的DNA碱基与皱纹区域接触，从而加速了dsDNA的变形。这些发现突出了皱纹在石墨烯与生物分子相互作用中的重要性，并加深了我们对石墨烯纳米毒性的一般理解。局部展开从第一个碱基对到下一个碱基对依次进行，直到末端。这种类似拉链的展开随后暴露出更多的DNA碱基与皱纹区域接触，从而加速了dsDNA的变形。这些发现突出了皱纹在石墨烯与生物分子相互作用中的重要性，并加深了我们对石墨烯纳米毒性的一般理解。