Terahertz spectroscopy for the isothermal detection of bacterial DNA by magnetic bead-based rolling circle amplification
Terahertz spectroscopy for the isothermal detection of bacterial DNA by magnetic bead-based rolling circle amplification
复制标题
通过基于磁珠的滚环扩增等温检测细菌 DNA 的太赫兹光谱
DOI：
10.1039/c7an01438d
复制
发表时间：
2017-12-21
期刊：
影响因子：
4.2
通讯作者：
Fu, Weiling
中科院分区：
文献类型：
--
作者：
Yang, Xiang;Yang, Ke;Fu, Weiling
由于各种应用的显著要求，对快速和灵敏的细菌检测的需求不断增加。本研究基于滚环扩增技术（rolling circle amplification，RCA）构建了一种用于细菌DNA等温检测的太赫兹（terahertz，THz）生物传感器。16 S rDNA的合成细菌特异性序列与挂锁探针（PLP）杂交，所述挂锁探针（PLP）在5'和3'末端含有与靶序列完全互补的序列。线性PLP通过连接环化以在识别靶序列时形成环状PLP;然后固定在磁珠（MB）上的捕获探针（CP）充当引物以初始化RCA。由于DNA分子在THz范围内的吸收比水分子小得多，因此MB表面上的RCA产物导致THz吸收的显著降低，这可以通过THz光谱灵敏地探测。我们的研究结果表明，0.12 fmol的合成细菌DNA和0.05 ng μ L-1的基因组DNA可以有效地检测使用这种方法。此外，该策略的特异性通过其对干扰细菌的低信号响应来证明。提出的策略不仅代表了一种新的方法，用于等温检测的目标细菌DNA，但也提供了一个通用的方法，灵敏和特异性的DNA生物传感器使用太赫兹光谱。
The demand for rapid and sensitive bacterial detection is continuously increasing due to the significant requirements of various applications. In this study, a terahertz (THz) biosensor based on rolling circle amplification (RCA) was developed for the isothermal detection of bacterial DNA. The synthetic bacterium-specific sequence of 16S rDNA hybridized with a padlock probe (PLP) that contains a sequence fully complementary to the target sequence at the 5' and 3' ends. The linear PLP was circularized by ligation to form a circular PLP upon recognition of the target sequence; then the capture probe (CP) immobilized on magnetic beads (MBs) acted as a primer to initialize RCA. As DNA molecules are much less absorptive than water molecules in the THz range, the RCA products on the surface of the MBs cause a significant decrease in THz absorption, which can be sensitively probed by THz spectroscopy. Our results showed that 0.12 fmol of synthetic bacterial DNA and 0.05 ng mu L-1 of genomic DNA could be effectively detected using this assay. In addition, the specificity of this strategy was demonstrated by its low signal response to interfering bacteria. The proposed strategy not only represents a new method for the isothermal detection of the target bacterial DNA but also provides a general methodology for sensitive and specific DNA biosensing using THz spectroscopy.