Although chirality is critical for molecular properties and functions, experimental quantification of chirality is lacking. Herein, we performed cyclic voltammetry (CV) under polarized magnetic fields to provide a unified scale to quantify and compare DNA chirality. We observed the largest electron spin polarization in DNA structures with opposite chiral senses, which is consistent with the effect of chiral-induced spin selectivity (CISS). Spin polarization is weaker among DNA topologies of the same chiral arrangement, with DNA triplexes exhibiting the strongest CISS. Within DNA duplexes, spin polarization is further reduced depending on the sequence, with fewer guanine–cytosine (GC) pairs displaying a weaker CISS likely due to localized variations in chirality. Surprisingly, spin polarization is vectorial along the DNA duplex while presenting the smallest variation when the transportation directions of electrons become opposite. The four factors, chiral sense, topology, sequence, and directionality of electron transportation, delineate hierarchical contributions to molecular chirality, with profound implications ranging from spintronics to molecular recognitions.

中文翻译：

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DNA 手性的电分析定量


尽管手性对分子性质和功能至关重要，但缺乏手性的实验定量。在此，我们在极化磁场下进行了循环伏安法 （CV），以提供统一的尺度来量化和比较 DNA 手性。我们在具有相反手性感觉的 DNA 结构中观察到最大的电子自旋极化，这与手性诱导的自旋选择性 （CISS） 的效果一致。在相同手性排列的 DNA 拓扑结构中，自旋极化较弱，DNA 三链体表现出最强的 CISS。在 DNA 双链体中，根据序列的不同，自旋极化进一步降低，较少的鸟嘌呤-胞嘧啶 （GC） 对显示出较弱的 CISS，这可能是由于手性的局部变化。令人惊讶的是，自旋极化沿 DNA 双链体呈矢量化，而当电子的传输方向相反时，其变化最小。这四个因素，即手性意义、拓扑结构、序列和电子传输的方向性，描绘了对分子手性的分层贡献，具有从自旋电子学到分子识别的深远影响。