Fabrication of micro free-flow electrophoresis chip by photocurable monomer binding microfabrication technique for continuous separation of proteins and their numerical simulation

Abstract

In this study, a simple, fast, and reliable method to fabricate a micro free-flow electrophoresis (μFFE) device on glass is presented. The two-dimensional depth channel in the chip was easily achieved by using a photocurable monomer (NOA 81) that served as the bonding material. In such a geometrical structure (two-dimensional depth channel), the effect of fluid behavior on the separation efficiency of micro free-flow zone electrophoresis (μFFZE) was simulated. The results of numerical simulation indicate that the pressure at the inlets may play an important role in the separation performance. Under the optimum separation conditions, four FITC-labeled amino acids were well separated, indicating the validity of the performance of the chip. Since the chip was fabricated by organic polymer bonding, it was easily recyclable through a simple re-fabrication process. The reproducibility of results from these recycling re-fabrication chips was investigated. The RSD of the resolution between FITC-L-glycine and FITC-L-phenylalanine was 5.3%. Furthermore, three FITC-labeled proteins were successfully separated with the resolution of 2.2 and 5.46, respectively, by using the coating of neutral liposome.

Continuous particle separation using pressure-driven flow-induced miniaturizing free-flow electrophoresis (PDF-induced μ-FFE)

“…The advantage offered by μ-FFE includes continuous, high-resolution separation with minimal sample quantities. This suggests the incorporation of μ-FFE as a micro-preparative part of a μTAS system, which is commonly used to separate biomolecules, such as proteins, peptides, DNA, and cells 19 .…”

“…Despite excellent performance, μ-FFE has several problems, including a complex fabrication process, gas bubble generation, and Joule heating 15 20 . Typically, in the manufacture of μ-FFE devices, the fabrication processes include multi-step etching, soft lithography, anodic bonding, and thermal bonding for integration of the internal electrodes 19 . Gas bubbles are inherently generated at the internal electrodes by water electrolysis and tend to distort separation and decrease the separation efficiency 20 .…”

Advancements in microfluidics for nanoparticle separation

“…176 Continuous separation of four types of amino acid and proteins, such as trypsin inhibitor and RNAse A, using microflow electrophoresis (μ-FFE) and its simulation has been reported. 177 In another report, Tekin and Gijs separated and purified proteins using antibodyconjugated magnetic nanoparticles with magnetophoresis. 90 DEP can also be used for protein fractionation, as a simulation and an experiment to concentrate protein using insulator-based DEP has been shown.…”

Reduced surface adsorption in 3D printed acrylonitrile butadiene styrene micro free‐flow electrophoresis devices

“…The drive for rapid production of µFFE devices has led to improved fabrication techniques such as the use of laser printer toner on glass as a substrate , multistep liquid‐phase lithography , multistep lamination , injection molding , and bonding etched glass with a photocurable polymer . These methods have proven to be faster and cheaper than typical glass photolithography techniques for µFFE device production.…”