Journal Article

High-Throughput Continuous-Flow Separation in a Micro Free-Flow Electrophoresis Glass Chip Based on Laser Microfabrication

Lin, Zijie, Xu, Jian, Song, Yunpeng, Cheng, Ya, Zhang, Aodong, Wang, Zhenhua, Li, Xiaolong, Li, Xin

2022

Overview

Micro free-flow electrophoresis (μFFE) provides a rapid and straightforward route for the high-performance online separation and purification of targeted liquid samples in a mild manner. However, the facile fabrication of a μFFE device with high throughput and high stability remains a challenge due to the technical barriers of electrode integration and structural design for the removal of bubbles for conventional methods. To address this, the design and fabrication of a high-throughput μFFE chip are proposed using laser-assisted chemical etching of glass followed by electrode integration and subsequent low-temperature bonding. The careful design of the height ratio of the separation chamber and electrode channels combined with a high flow rate of buffer solution allows the efficient removal of electrolysis-generated bubbles along the deep electrode channels during continuous-flow separation. The introduction of microchannel arrays further enhances the stability of on-chip high-throughput separation. As a proof-of-concept, high-performance purification of fluorescein sodium solution with a separation purity of ~97.9% at a voltage of 250 V from the mixture sample solution of fluorescein sodium and rhodamine 6G solution is demonstrated.

• Publisher: MDPI AG,MDPI
• Subject: continuous-flow separation / Electric fields / Electrodes / Electrolysis / Electrophoresis / Etching / femtosecond laser microfabrication / Fluorescein / Glass / glass microfluidics / laser-assisted chemical etching / Lasers / micro free-flow electrophoresis / Microtechnology