A micromachined chip-based electrospray source for mass spectrometry
A micromachined chip-based electrospray source for mass spectrometry
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DOI：
10.1021/ac990967p
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发表时间：
2000-01-15
影响因子：
7.4
通讯作者：
Lee, TD
中科院分区：
文献类型：
--
作者：
Licklider, L;Wang, XQ;Lee, TD
描述了一种在硅芯片上制造质谱电喷雾源的微加工工艺。该工艺利用聚合物（聚对二甲苯）层形成一个由腔室、过滤器、通道和空心针结构（电喷雾发射器）组成的系统，这些结构延伸到硅衬底边缘以外一毫米以上。使用光刻胶作为牺牲层有利于长通道的创建。通过通过硅衬底蚀刻的端口访问芯片上的通道结构，该衬底也用作样品储存库。由两个塑料板和弹性体垫片组成的可重复使用的芯片支架提供了将芯片安装在质谱仪入口前面并进行电气和气体连接的手段。电喷雾发射器有5 μ m × 10 μ m矩形开口锥形尖端。尖端的形状可以根据在最后的等离子蚀刻过程中用于保护聚对二甲苯结构的掩膜的形状而变化。对二甲苯发射器是物理上坚固耐用，只需要一个高电场，以实现稳定的电喷涂操作在一段时间的几个小时。与传统玻璃或熔融二氧化硅发射器的直接比较表明，在信号强度和稳定性、光谱质量和耐用性方面，其性能非常相似。对混合色氨酸的自动质谱/质谱分析并不困难，并且与使用传统纳米喷雾装置分析相同样品的结果几乎相同。这项工作表明，高效的电喷雾质谱界面可以与其他片上结构集成，并使用批量工艺批量生产。
A micromachining process is described for fabricating a mass spectrometry electrospray source on a silicon chip. The process utilizes polymer (parylene) layers to form a system of chambers, filters, channels, and hollow needle structures (electrospray emitters) that extend more than a millimeter beyond the edge of the silicon substrate. The use of photoresist as the sacrificial layer facilitates the creation of long channels. Access to the channel structures on the chip is through a port etched through the silicon substrate that also serves as a sample reservoir. A reusable chip holder consisting of two plastic plates and an elastomer gasket provides the means to mount the chip in front of the mass spectrometer inlet and make electrical and gas connections. The electrospray emitters have tapered tips with 5 mu m x 10 mu m rectangular openings. The shape of the tip can be varied depending on the shape of the mask used to protect the parylene structures during the final plasma etch. The parylene emitters are physically robust and require only a high electric field to achieve stable electrospray operation over a period of a few hours. Direct comparisons with conventional glass or fused silica emitters indicated very similar performance with respect to signal strength and stability, spectral quality, and endurance. The automated MS/MS analysis of a mixture of tryptic peptides was no more difficult and yielded nearly identical results as the analysis of the same sample using a conventional nanospray device. This work demonstrates that an efficient electrospray interface to mass spectrometry can be integrated with other on-chip structures and mass-produced using a batch process.