基于LiCl盐浓度梯度的固态纳米孔DNA分子检测

针对生物分子通过固态纳米孔的速度过快所引起的低时间分辨率问题,采用氯化锂(LiCl)盐溶液和盐浓度梯度相结合的方法来提高检测过程中信号的时间分辨率.通过在氮化硅薄膜上制备固态纳米孔,并在纳米孔两端施加LiCl盐浓度梯度进行DNA分子检测,发现DNA分子信号频率随LiCl盐浓度梯度的增加呈指数递增趋势,10倍浓度梯度下的...

Detection of DNA Molecule with Solid-State Nanopores Based on LiCl Salt Concentration Gradient

For the problem of low time resolution caused by the excessively fast speed of biomolecules translocating through solid-state nanopores,a method of combining lithium chloride(LiCl)salt solution with salt concentration gradient was used to improve the time resolution of the signal during detection.By preparing solid-state nanopores on the silicon nitride thin films and applying LiCl salt concentration gradients across the nanopores to detect DNA molecules,it is found that the DNA molecular signal frequency shows an exponential increasing trend with the increase of the LiCl salt concentration gradient.The signal frequency at 10-fold concentration gradient is about 107 times that at the symmetric concentration,which greatly increases the efficiency of DNA molecules captured by nanopores per unit time.When the samples are detected at 10-fold concentration gradient,the translocation time of the DNA molecular reaches(10.22±0.41)ms.Compared with the detection result((0.93±0.07)ms)at the symmetric concentration,the translocation time is delayed by one order,which greatly improves the detection sensitivity of DNA molecules.The research results indicate that applying different LiCl salt concentration gradients across the solid-state nanopores can significantly improve the time resolution of DNA molecules detection by nanopores,thereby effectively improving the sensitivity of the DNA molecules detection by nanopores.