Luminescence monitoring of DNA intercalator complexes is important for assessing their localisation and targeting: We report herein a luminescent hetero-trimetallic complex with europium as a luminescent reporter and two attached platinum acetylide terpyridyl units as the DNA recognition units. The ligand, based on a bisamide derivative of diethylenetriaminepentaacetic acid functionalized with two ethynyl groups, provides a backbone to anchor two platinum terpyridyl units, Pt-tpy, leading to the hairpin-shaped heterometallic complex 1. We also prepared a related mono-nuclear platinum complex 2 to compare its intercalation properties with 1. Linear dichroism, UV–visible and melting experiments show the ability of both complexes to interact with calf thymus DNA, with linear dichroism confirming intercalation and demonstrating the expected greater DNA stiffening by the bis-intercalator 1. Importantly, the tri-metallic complex 1 shows a three-fold enhancement in europium luminescence upon addition of calf thymus DNA; other mono-intercalator lanthanide designs have commonly shown a decrease in emission on binding. The ability of the complex to monitor DNA interactions gives the potential use as a luminescence switch in sensing experiments and highlights the design of heterometallic bis-intercalator complexes as an effective approach for DNA-responsive sensitisation of a lanthanide luminescence signal.

DNA嵌入剂复合物的发光监测对于评估其定位和靶向性很重要：我们在此报告了一种发光的杂三金属复合物，其中euro为发光报告分子，两个连接的乙炔基铂吡啶基吡啶单元为DNA识别单元。该配体基于被两个乙炔基官能化的二亚乙基三胺五乙酸的双酰胺衍生物，提供了一个锚固两个铂叔吡啶基单元Pt-tpy的骨架，从而形成了发夹状异金属络合物1。我们还制备了一种相关的单核铂络合物2，以将其嵌入性能与1进行比较。。线性二色性，紫外可见和熔融实验显示了两种复合物与小牛胸腺DNA相互作用的能力，线性二色性证实了嵌入，并证明了双嵌入剂1有望增强DNA的刚性。重要的是，添加小牛胸腺DNA后，三金属配合物1的euro发光增强了3倍。其他单嵌入剂镧系元素设计通常显示出结合时发射的减少。该复合物监测DNA相互作用的能力使其有可能用作传感实验中的发光开关，并着重强调了异金属双嵌入物复合物的设计是对镧系元素发光信号进行DNA响应敏化的有效方法。