A fully integrated monolithic microchip electrospray device for mass spectrometry
A fully integrated monolithic microchip electrospray device for mass spectrometry
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DOI：
10.1021/ac000325y
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发表时间：
2000-09-01
影响因子：
7.4
通讯作者：
Zhang, S
中科院分区：
文献类型：
--
作者：
Schultz, GA;Corso, TN;Zhang, S
开发了一种新型微加工喷嘴，用于从微流体装置中电喷雾液体，以进行质谱分析。电喷雾装置由单片硅衬底制造，使用深反应离子蚀刻和其他标准半导体技术从硅晶片的平坦表面蚀刻喷嘴。通道从喷嘴的尖端穿过晶片延伸到蚀刻到晶片的相对平坦表面中的储存器。使用这种方法已经制造出直径小至15 μ m的喷嘴。微制造的电喷雾装置提供了产生液体样品的纳米电喷雾的可再现的、可控的和鲁棒的手段。将电喷雾装置与大气压电离飞行时间质谱仪连接，使用以低纳升/分钟流速连续输注测试化合物。使用10个喷嘴的喷嘴间信号强度再现性被证明为12%，单喷嘴信号稳定性通常小于4%相对标准偏差（RSD）。溶剂组合物已经被电喷雾，范围从100%有机物到100%水性物。以100 nL/min输注10 nM细胞色素c溶液hl 1005水的信噪比为450：1。将微芯片电喷雾喷嘴与牵拉毛细管进行比较，以获得小分子和大分子的整体灵敏度和信号稳定性。微芯片电喷雾喷嘴的灵敏度比牵拉毛细管的灵敏度提高了1.5-3倍，微芯片的信号稳定性为2- 4%RSD，而牵拉毛细管的信号稳定性为4-10%。迄今为止，电喷雾装置的使用寿命已经超过了8小时的连续操作，并且对于典型的微流体应用应该是足够的。电喷雾装置的总体积小于25 pL，使其适合与微流体分离装置组合。
A novel microfabricated nozzle has been developed for the electrospray of liquids from microfluidic devices for analysis by mass spectrometry. The electrospray device was fabricated from a monolithic silicon substrate using deep reactive ion etching and other standard semiconductor techniques to etch nozzles from the planar surface of a silicon wafer. A channel extends through the wafer from the tip of the nozzle to a reservoir etched into the opposite planar surface of the wafer. Nozzle diameters as small as 15 mu m have been fabricated using this method. The microfabricated electrospray device provides a reproducible, controllable, and robust means of producing nanoelectrospray of a liquid sample. The electrospray device was interfaced to an atmospheric pressure ionization time-of-flight mass spectrometer using continuous infusion of test compounds at low nanoliter-per-minute now rates. Nozzle-to-nozzle signal intensity reproducibility using 10 nozzles was demonstrated to be 12% with single-nozzle signal stability routinely less than 4% relative standard deviation (RSD). Solvent compositions have been electrosprayed ranging from 100% organic to 100% aqueous. The signal-to-noise ratio from the infusion of a 10 nM cytochrome c solution hl 1005 water at 100 nL/min was 450:1. Microchip electrospray nozzles were compared with pulled capillaries for overall sensitivity and signal stability for small and large molecules. The microchip electrospray nozzles showed a 1.5-3-times increase in sensitivity compared with that from a pulled capillary, and signal stability with the microchip was 2-4% RSD compared with 4-10% with a pulled capillary. Electrospray device lifetimes achieved thus far have exceeded 8 h of continuous operation and should be sufficient for typical microfluidic applications. The total volume of the electrospray device is less than 25 pL, making it suitable for combination with microfluidic separation devices.