Use of β-cyclodextrin-tethered cationic polymer based fluorescence enhancement of pyrene and hybridization chain reaction for the enzyme-free amplified detection of DNA was written by Song, Chunxia;Li, Bingjie;Yang, Xiaohai;Wang, Kemin;Wang, Qing;Liu, Jianbo;Huang, Jin. And the article was included in Analyst (Cambridge, United Kingdom) in 2017.Reference of 2387-23-7 This article mentions the following:
Herein, we proposed an enzyme-free strategy for the amplified detection of DNA by combining the efficient fluorescence enhancement capability of a β-cyclodextrin-tethered cationic polymer (cationic polyβ-CD) to pyrene with the amplification capability of target DNA triggered hybridization chain reaction (HCR). Cationic polyβ-CD with pos. charge was synthesized. Two hairpin probes, H1 and H2, were employed in the system and the pyrene-labeled H2 was chosen as the signal unit. The pyrene attached on the sticky end of H2 was flexible and there was strong electrostatic interaction between cationic polyβ-CD and neg.-charged H2, so pyrene could easily enter the cavity of CD that is tethered on the cationic polymer, accompanied by significant fluorescence enhancement. Once target DNA was introduced, HCR was triggered to form a rigid long dsDNA polymer with pyrene attached on it. The pyrene was hardly able to enter the cavity of cationic polyβ-CD because of steric hindrance, leading to a weak fluorescent signal. Owing to the efficient pyrene fluorescence enhancement of cationic polyβ-CD and the amplified capability of HCR, an enzyme-free sensitive detection of target DNA was achieved with a detection limit of 0.1 nM and high selectivity. In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Reference of 2387-23-7).
1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. The presence of the amide group –C(=O)N– is generally easily established, at least in small molecules. It can be distinguished from nitro and cyano groups in IR spectra. Amides exhibit a moderately intense νCO band near 1650 cm−1. By 1H NMR spectroscopy, CONHR signals occur at low fields. In X-ray crystallography, the C(=O)N center together with the three immediately adjacent atoms characteristically define a plane.Reference of 2387-23-7
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics