Silicon nanowire arrays for the preconcentration and separation of trace explosives vapors.
Silicon nanowire arrays for the preconcentration and separation of trace explosives vapors.
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用于预浓缩和分离痕量爆炸物蒸气的硅纳米线阵列。
DOI：
10.1016/j.chroma.2019.03.045
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
P. Pehrsson
中科院分区：
文献类型：
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作者：
B. Giordano;Daniel C. Ratchford;Kevin J. Johnson;P. Pehrsson
硅纳米线 (SiNW) 阵列被证明是预浓缩痕量硝基芳香族化合物并随后通过阵列焦耳加热解吸的合适平台。阵列由硅晶片制成，硅晶片包含夹在高电导率 p 型硅层之间的外延生长的低电导率本征硅层。电流通过纳米线导致阵列加热期间纳米线温度超过 200°C，这一点通过使用 Si 拉曼谱带在~520 cm-1 处的温度相关位移进行了验证。在阵列上实现分析物蒸气预浓缩和部分分离，分析物浓度比室温下的饱和蒸气浓度低近两个数量级。确定解吸载气流速和温度对预浓缩和解析感兴趣分析物的能力的影响。 2,6-二硝基甲苯 (2,6-DNT) 和 2,4-二硝基甲苯 (2,4-DNT) 的标称蒸气浓度为 800 pptv，采样时间为 1 分钟（1.1ng 标称质量负载），三硝基甲苯 (TNT) 的标称蒸气浓度为 65 pptv，采样时间为 10 分钟（1.1ng 标称质量负载）。质量负载）。
Silicon nanowire (SiNW) arrays are demonstrated as a suitable platform for the preconcentration of trace nitroaromatic compounds and subsequent desorption via Joule heating of the array. Arrays are fabricated from Si wafers containing an epitaxially grown layer of low conductivity intrinsic Si sandwiched between layers of high conductivity p-type Si. Passage of current through the nanowires results in nanowire temperatures in excess of 200 °C during heating of the arrays as verified by using the temperature-dependent shift of the Si Raman band at ˜520 cm−1. Analyte vapor preconcentration and partial separation is achieved on the array at analyte concentrations nearly two orders-of-magnitude below saturated vapor concentrations at room temperature. The effects of desorption carrier gas flow rate and temperature on the ability to preconcentrate and resolve the analytes of interest are determined. 2,6-dinitrotoluene (2,6-DNT) and 2,4-dinitrotoluene (2,4-DNT) were detected at nominal vapor concentrations of 800 pptvwith a 1 min sample time (1.1 ng nominal mass load) and trinitrotoluene (TNT) was detected at a nominal vapor concentration of 65 pptvwith a 10 min sample time (1.1 ng nominal mass load).