Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada.
Department of Mechanical Engineering, 35 Baekbeom-ro (Sinsu-dong), Mapo-gu, Sogang University, Seoul, 04107, Korea.
Sci Rep. 2017 Jun 14;7(1):3535. doi: 10.1038/s41598-017-03846-y.
This report discusses the first demonstration of electrophoresis assisted time-of-flow mass spectrometry using 'U' shaped hollow nanomechanical resonators (HNR). Capillary electrophoresis was coupled with the HNR based mass detection to overcome low ionic conductivity of channels embedded in the HNR preventing direct in-situ electrophoretic separation. The flow of analytes through the HNR was achieved by balancing the hydrodynamic pressure to override the electromotive force and inhibit the motion of analytes towards the anode for capillary electrophoresis. The resonance frequency shifts of the HNR vibrating around 1.5 MHz were correlated with the time of the passage of the protein bands to construct the mass spectrum. The proposed concept was demonstrated by constructing a mass spectrum of egg white proteins in the molecular weight range of 14-250 kDa. When compared to regular polyacrylamide gel electrophoresis, our method not only provides a precise and fast readout but also avoids the use of chemical staining. This study paves a new route for low-cost and on-chip mass spectrometers with ultra-miniaturized dimensions.
本报告讨论了首次使用“U”型中空纳米机械谐振器（HNR）进行电泳辅助流动时间质谱分析的演示。将毛细管电泳与基于 HNR 的质量检测相结合，克服了嵌入 HNR 中的通道的低离子电导率，从而阻止了直接原位电泳分离。通过平衡流体动力学压力以克服电动电势并抑制分析物向阳极的运动来实现分析物在 HNR 中的流动，从而实现毛细管电泳。HNR 以约 1.5 MHz 的谐振频率移动与蛋白质带通过的时间相关联，以构建质谱。通过在 14-250 kDa 的分子量范围内构建蛋清蛋白的质谱，验证了该概念。与常规的聚丙烯酰胺凝胶电泳相比，我们的方法不仅提供了精确和快速的读数，而且避免了化学染色的使用。这项研究为具有超小型尺寸的低成本和片上质谱仪开辟了新途径。
