Design of a Room-Temperature Phosphorescence-Based Molecular Beacon for Highly Sensitive Detection of Nucleic Acids in Biological Fluids
Design of a Room-Temperature Phosphorescence-Based Molecular Beacon for Highly Sensitive Detection of Nucleic Acids in Biological Fluids
复制标题
用于生物体液中核酸高灵敏检测的室温磷光分子信标的设计
DOI：
10.1021/ac102710w
复制
发表时间：
2011-02-15
影响因子：
7.4
通讯作者：
Yuan, Jingli
中科院分区：
文献类型：
--
作者：
Li, Jishan;Zhou, Wenyu;Yuan, Jingli
超灵敏荧光分析或复杂样品中重要分子的监测对于许多生物学研究、临床诊断和法医调查非常重要，其主要障碍是来自环境中普遍存在的内源荧光成分的背景信号。在此，设计了一种基于室温磷光 (RTP) 的分子信标 (MB)，采用氯磺酰化四齿 β-二酮 (L) 和猝灭剂 BHQ-2 的 Eu3+ 复合物，用于高灵敏度检测生物液体中的 DNA 序列。 Eu3+ 的络合。与配体L形成强发光配合物EuL2。但当EuL2和BHQ-2标记在具有发夹结构的DNA分子的两端时，由于信标的茎闭合构象，EuL2的发光被BHQ-2猝灭。由于探针分子的背景发光非常低，当引入纳摩尔目标序列时，信号增强了 200 倍以上。这种灵敏度比传统基于荧光的分子信标达到的水平高出约 20 倍。此外，由于Eu3+配合物的发光寿命比背景长得多（约0.8 ms）（
Ultrasensitive fluorescent analysis or monitoring of significant molecules in complex samples is important for many biological studies, clinical diagnosis, and forensic investigations, the major obstacle for which is the background signals from ubiquitous endogenous fluorescent components of the environments. Herein, a room-temperature Phosphorescence (RTP)based molecular beacon (MB), employing a Eu3+ complex of chlorosulfonylated tetradentate beta-diketone (L) and the quencher BHQ-2, was engineered for highly sensitive detection of DNA sequences in biological fluids. Complexation of Eu3+. with the ligand L formed a strongly luminescent complex EuL2. But when EuL2 and BHQ-2 were labeled to two ends of a DNA molecule with hairpin structure, the luminescence of EuL2 was quenched by BHQ-2 due to the stem-closed conformation of the beacon. Due to very low background luminescence from the probe molecule, >200-fold signal enhancement was achieved when nanomolar target sequence was introduced. This sensitivity is about 20-fold higher than the level achieved with conventional fluorescence-based molecular beacons. Furthermore, because the Eu3+ complex has a much longer luminescence lifetime (approximate to 0.8 ms) than that of the background (