High performance thread-based CE-EC system with variable volume injection capability and 3D detection electrodes

This study develops a high-performance thread-based microfluidic device with variable volume injection capability and 3-dimensional (3D) detection electrodes for capillary electrophoresis electrochemical (CE-EC) detection of biosamples. PMMA substrate with concave 3D electrodes produced with the hot-embossing method is used to enhance the sensing performance of the CEEC system. Results show that the chip with 3D sensing electrodes exhibits around 10-fold current response than that obtained using the chip with conventional 2D sensing electrodes for detecting 6.25 μM K3Fe (CN)6. In addition, the developed thread-based microfluidic system is capable of injecting variable sample volumes into the separation thread simply by winding different turns of the injection thread on the separation thread. The developed concave-shaped three-dimensional electrode provides a simple and low-cost method for thread-based CEEC applications.