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

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.