In this study, we report the synthesis of water-soluble MoS₂ quantum dots (MoS₂, QD) by a hydrothermal one-step method. These QDs were mixed in an aqueous solution of 2 kbp DNA to form fluorescent nanocomposite hydrogels at a very low concentration of the nucleic acid (1.0% (w/v), normal gelation occurs at 2% (w/v)). The melting temperature T_melt of these gels was 50 ± 2 °C while the hydrogels melt at 40 ± 2 °C, and the low-frequency storage modulus/gel strength G₀ was 40 ± 2 Pa (9 ± 2 Pa for hydrogel). This clearly implied that MoS₂ acted as a pseudo-cross-linker in the nanocomposite hydrogel formation. The remarkable synergy of interaction between DNA and QDs can be gauged from the fact that the gel strength and melting temperature increased with QD content regardless of the fact that both carried negative charge. Dynamic light scattering studies showed arrested dynamics at the onset of gelation, and the gel transition time or ergodicity breaking time τ_EB decreased with the increase in QD concentration. Small-angle X-ray scattering data captured the internal structure of these gels. Thus, we have a unique nanocomposite DNA-based hydrogel that is fluorescent, and in 2-D, this soft matter remarkably exhibits the behavior of an organic light-emitting diode (OLED), which imparts sufficient novelty to this work.

中文翻译：

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用于有机发光二极管的荧光MoS ₂量子点-DNA纳米复合水凝胶

在这项研究中，我们报告了通过水热一步法合成水溶性MoS ₂量子点（MoS ₂，QD）。将这些量子点在2 kbp DNA的水溶液中混合，以非常低的核酸浓度（1.0％（w / v），在2％（w / v）发生正常胶凝）形成荧光纳米复合水凝胶。熔化温度Ť_熔化这些凝胶的溶液50±2℃，同时水凝胶在40±2℃熔化，和低频储能模量/凝胶强度ģ ₀为40±2帕（9±2 Pa下的水凝胶） 。这显然暗示着MoS ₂在纳米复合水凝胶的形成过程中起伪交联剂的作用。DNA和QD之间相互作用的显着协同作用可以通过以下事实来衡量：凝胶强度和熔化温度随QD含量的增加而增加，而与两者均带有负电荷无关。动态光散射研究在凝胶化的开始显示出被捕动力学，和断裂时间τ凝胶转变时间或遍历性_EB与QD浓度的增加而降低。小角X射线散射数据捕获了这些凝胶的内部结构。因此，我们拥有一种独特的基于荧光的纳米复合物DNA水凝胶，在二维中，这种软物质显着展现了有机发光二极管（OLED）的行为，为这项工作赋予了足够的新颖性。