Unwinding the double helix of DNA, the premier step of DNA replication and translation, is crucial for the transmission of biological genetic information. Recent studies have demonstrated that mid-infrared (mid-IR) radiation can promote the unwinding of DNA double helixes at the molecular level. However, the limited skin depth prevents mid-IR from fully interacting with DNA molecules due to the thicker water layer and significant temperature rise, leading to uncertainty in the mechanism of action. Here, we demonstrate a direct experimental method in which mid-IR can promote DNA unwinding rather than just thermal effects by significantly reducing the water film to 300 μm. The experimental results indicate that mid-IR promotes DNA double-helix dissociation by 7 times, under the temperature of 40 °C. Even under external cooling conditions at 30 °C, mid-IR can still promote an unwinding process, further verifying the effect of the mid-IR field on DNA duplexes. Besides, the experimental results are consistent with the simulation results based on molecular dynamics. Our research results offer an efficient approach for the exploration of in vivo experiments of mid-IR technology in gene biology, with broad potential applications in the rapid detection of nucleic acids, bioinformatics, and in vivo drug delivery.

中文翻译：

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中红外辐射加速 DNA 解旋

解开 DNA 双螺旋是 DNA 复制和翻译的第一步，对于生物遗传信息的传递至关重要。最近的研究表明，中红外（mid-IR）辐射可以在分子水平上促进DNA双螺旋的解旋。然而，由于水层较厚和温度显着升高，有限的集肤深度阻碍了中红外与DNA分子充分相互作用，导致作用机制的不确定性。在这里，我们演示了一种直接实验方法，其中中红外可以通过将水膜显着减小至 300 μm 来促进 DNA 解旋，而不仅仅是热效应。实验结果表明，在40℃的温度下，中红外促进DNA双螺旋解离7倍。即使在30°C的外部冷却条件下，中红外仍然可以促进解旋过程，进一步验证了中红外场对DNA双链体的影响。此外，实验结果与基于分子动力学的模拟结果一致。我们的研究成果为探索基因生物学中红外技术的体内实验提供了一种有效的方法，在核酸快速检测、生物信息学和体内药物递送方面具有广泛的潜在应用。