In this work, the interaction of 1-butyl-3-methylimidazolium methanesulfonate ([C₄mim][MS]) and 1-hexyl-3-methylimidazolium methanesulfonate ([C₆mim][MS]) with calf thymus deoxyribonucleic acid (ctDNA) were investigated firstly by fluorescence spectra and UV absorption spectra, respectively. Fluorescence of [C_nmim][MS] (n = 4, 6) was quenched by ctDNA through static quenching. Groove binding between [C_nmim][MS] (n = 4, 6) and ctDNA was proved by UV absorption spectra, single-stranded and double-stranded DNA studies, iodide quenching studies and fluorescence polarization measurements. Binding constants of ctDNA with [C_nmim][MS] (n = 4, 6) were calculated at different temperatures (285 K, 298 K, 310 K), which indicated that the binding force of [C₆mim][MS]-ctDNA system was larger than that of [C₄mim][MS]-ctDNA system, and the binding force increased with increasing IL-alkyl chain length. The thermodynamic parameter results suggested that there existed electrostatic and hydrophobic interactions between the ctDNA with [C_nmim][MS] (n = 4, 6), and the hydrophobic interaction played the major role (at the concentration of study) in the interaction process of ctDNA with [C_nmim][MS] (n = 4, 6). These results may help us to reveal the interaction mechanism of ionic liquids (ILs) with ctDNA and demonstrate the effect of alkyl chain length of the cation on the binding constant of ILs-ctDNA interaction.

在这项工作中，甲基磺酸1-丁基-3-甲基咪唑鎓盐（[C ₄ mim] [MS]）和甲基磺酸1-己基-3-甲基咪唑鎓盐[[C ₆ mim] [MS]）与小牛胸腺脱氧核糖核酸（首先通过荧光光谱和紫外吸收光谱研究。[C _n mim] [MS]（n  =  4，6）的荧光通过ctDNA通过静态淬灭来淬灭。[C _n mim] [MS]（n  =  4，6）与ctDNA之间的凹槽结合通过紫外吸收光谱，单链和双链DNA研究，碘化物猝灭研究和荧光偏振测量得到证明。ctDNA与[C _n的结合常数在不同温度（285 K，298 K，310 K）下计算出mim] [MS]（n  =  4，6），这表明[C ₆ mim] [MS] -ctDNA系统的结合力大于C ₄ mim] [MS] -ctDNA系统的结合力，且结合力随IL-烷基链长度的增加而增加。热力学参数结果表明，ctDNA与[C _n mim] [MS]之间存在静电和疏水相互作用（n  =  4，6），并且疏水相互作用在相互作用中起主要作用（在研究集中） [C _n mim] [MS]处理ctDNA的过程（n  =  4，6）。这些结果可能有助于我们揭示离子液体（ILs）与ctDNA的相互作用机理，并证明阳离子的烷基链长度对ILs-ctDNA相互作用的结合常数的影响。