Using dual-polarization interferometry to study surface-initiated DNA hybridization chain reactions in real time.
Using dual-polarization interferometry to study surface-initiated DNA hybridization chain reactions in real time.
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DOI：
10.1016/j.bios.2013.08.005
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发表时间：
2014-01
影响因子：
12.6
通讯作者：
Fujian Huang;Pingping Xu;Haojun Liang
中科院分区：
文献类型：
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作者：
Fujian Huang;Pingping Xu;Haojun Liang
在这项研究中，我们使用双偏振干涉法来研究固液界面上的DNA杂交链反应（HCR）。我们监测的影响，在质量，厚度和密度的固定化引发剂上的后续HCR在各种盐浓度的变化。在低盐浓度下，单链DNA（ssDNA）引发剂均匀地附着到芯片表面。在高盐浓度下，其在固定化过程开始时位于表面上，但是接近的ssDNA迫使预固定的ssDNA链延伸到溶液中，这是由于预吸附和接近的ssDNA链之间的静电排斥增加。注入H1和H2的混合物最初增加了膜的质量和厚度，但此后厚度减小。这些变化表明，形成的长双链DNA位于表面，而不是延伸到溶液中，从而抑制了随后释放的H1和H2单链部分的起始活性。增加盐浓度可提高HCR效率和反应速率。固定在5′端的引发剂ssDNA的HCR效率高于固定在3′端的引发剂ssDNA的HCR效率，表明H1和H2的单链部分靠近芯片表面的释放相对于延伸到溶液中的释放降低了引发活性。
In this study we used dual-polarization interferometry to investigate DNA hybridization chain reactions (HCRs) at solid–liquid interfaces. We monitored the effects of variations in mass, thickness, and density of the immobilized initiator on the subsequent HCRs at various salt concentrations. At low salt concentrations, the single-stranded DNA (ssDNA) initiator was attached uniformly to the chip surface. At high salt concentrations, it lay on the surface at the onset of the immobilization process, but the approaching ssDNA forced the pre-immobilized ssDNA strands to extend into solution as a result of increased electrostatic repulsion between the pre-adsorbed and approaching ssDNA chains. Injection of a mixture of H1 and H2 increased the mass and thickness of the films initially, but thereafter the thickness decreased. These changes indicate that the long double-stranded DNA that formed lay on the surface, rather than extended into the solution, thereby suppressing the subsequent initiation activity of the released single-strand parts of H1 and H2. Increasing the salt concentration increased the HCR efficiency and reaction rate. The HCR efficiency of the initiator ssDNA immobilized on its 5′ end was higher than that immobilized on its 3′ end, suggesting that the released single-strand parts of H1 and H2 close to the chip surface decreased the initiation activity relative to those of the ones extending into solution.