Department of Applied Chemistry for Environment, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji-shi, Tokyo 192-0397, Japan.
Phys Chem Chem Phys. 2019 Oct 24;21(41):22732-22739. doi: 10.1039/c9cp03285a.
Dimidium (3,8-diamino-5-methyl-6-phenylphenanthridinium: NH2PhP) is a well-known fluorophore as a DNA probe, although its fluorescence enhancement mechanism is not clear. In this study, we investigated the fluorescence enhancement mechanism of NH2PhP on a clay surface by observing the fluorescence behavior. Four systematically selected phenanthridinium derivatives (PDs): NH2PhP, 3,8-bisdimethylamino-5-methyl-6-phenylphenanthridinium (NMe2PhP), 5-methyl-6-phenylphenanthridinium (PhP) and 5-methylphenanthridinium (P) and synthetic clay were used as guest and host materials, respectively. It was revealed that the suppression of hydrogen bonding with water (N-HOH or NH-OH2) is the dominant factor for the fluorescence enhancement on the clay surface for NH2PhP and NMe2PhP. In addition, judging from the fluorescence enhancement for NH2PhP, NMe2PhP and PhP and no fluorescence enhancement for P on the clay surface, the suppression of rotation of the phenyl ring was indicated to make a partial contribution to the fluorescence enhancement mechanism. Because the fluorescence enhancement behavior was quite similar on the clay surface and in DNA, the obtained results afford an important clue to discuss the fluorescence enhancement mechanism of NH2PhP in DNA.
二聚体(3,8-二氨基-5-甲基-6-苯基菲啶鎓:NH2PhP)是一种众所周知的荧光团,可用作 DNA 探针,但其荧光增强机制尚不清楚。在这项研究中,我们通过观察荧光行为研究了 NH2PhP 在粘土表面上的荧光增强机制。选择了四种系统的菲啶鎓衍生物(PDs):NH2PhP、3,8-二甲基氨基-5-甲基-6-苯基菲啶鎓(NMe2PhP)、5-甲基-6-苯基菲啶鎓(PhP)和 5-甲基菲啶鎓(P)以及合成粘土作为客体和主体材料。结果表明,抑制与水的氢键(N-HOH 或 NH-OH2)是 NH2PhP 和 NMe2PhP 在粘土表面上荧光增强的主要因素。此外,从 NH2PhP、NMe2PhP 和 PhP 在粘土表面上的荧光增强以及 P 无荧光增强的情况来看,抑制苯基环的旋转对荧光增强机制也有一定的贡献。由于在粘土表面和 DNA 中的荧光增强行为非常相似,因此获得的结果为讨论 NH2PhP 在 DNA 中的荧光增强机制提供了重要线索。