Monolithic nanofluid sieving structures for DNA manipulation
Monolithic nanofluid sieving structures for DNA manipulation
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DOI：
10.1116/1.590419
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发表时间：
1998-11-01
影响因子：
1.4
通讯作者：
Craighead, HG
中科院分区：
文献类型：
--
作者：
Turner, SW;Perez, AM;Craighead, HG
提出了一种制备用于 DNA 电泳的二维人工凝胶的新技术。该技术与以前的方法的不同之处在于，整个器件使用源自半导体电子制造的专门平面处理技术制造为单片单元。电介质底板和顶板之间的流体间隙的高度由通过湿化学蚀刻去除的牺牲层的厚度确定。这样可以精确控制整个硅片上的间隙并具有出色的均匀性。 1.5 厘米设备上的地板到天花板高度控制优于 5 纳米。电子束光刻用于在牺牲层中定义 100 nm 障碍物的方形阵列。在牺牲层上施加化学气相沉积氮化硅。反应离子蚀刻（RTE）用于在氮化物层中创建接入孔，以便可以通过湿化学蚀刻去除牺牲层。湿法蚀刻后，使用极低温氧化物 (VLTO) 二氧化硅重新密封接入孔。最后，用RIE在装置两端打开加样窗口，以便引入水溶液中的DNA并观察其在电场影响下的运动。 DNA 分子用荧光染料标记，并用光学显微镜通过电介质顶层进行观察。电泳迁移率针对两种不同的 DNA 链长度（43 和 7.2 kbase）进行测量。报告了在 15 mm 设备上施加 2 至 20 V 电压时两种 DNA 长度的速度。在某些电压下，速度相差近 2 倍。(C) 1998 年美国真空协会。 [S0734-211X(98)15106-5]。
A new technique for fabricating two-dimensional artificial gels for DNA electrophoresis is presented. The technique differs from previous approaches in that the entire device is fabricated as a monolithic unit using exclusively planar processing techniques adapted from semiconductor electronics fabrication. The height of the fluid gap between the dielectric floor and ceiling is determined by the thickness of a sacrificial layer which is removed by a wet chemical etch. This allows precise control and excellent uniformity of the gap over an entire silicon wafer. Floor-to-ceiling height control better than 5 nm has been demonstrated over a 1.5 cm device. Electron beam lithography is used to define a square array of 100 nm obstructions in the sacrificial layer. Chemical vapor deposition silicon nitride is applied over the sacrificial layer. Reactive ion etching (RTE) is used to create access holes in the nitride layer, so that the sacrificial layer can be removed with a wet chemical etch. After the wet etch, the access holes are resealed with very low temperature oxide (VLTO) silicon dioxide. Finally, loading widows are opened with RIE at both ends of the device so that DNA in aqueous solution can be introduced and its motion under the influence of an electric field can be observed. The DNA molecules are labeled with a fluorescent dye and observed through the dielectric top layers with an optical microscope. The electrophoretic mobility is measured for two different DNA chain lengths, 43 and 7.2 kbase. The velocity for both DNA lengths is reported for an applied potential between 2 and 20 V over the 15 mm device. At some voltages the velocities differed by nearly a factor of 2. (C) 1998 American Vacuum Society. [S0734-211X(98)15106-5].