Development of Capillary Electrophoresis Chip Intergrated with End-Channel Off-Chip Electrochemical Planar Electrodes

• Main Authors: Yi-Tong Pan, 潘羿彤
• Other Authors: 吳靖宙
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/7xsfe7

碩士 === 國立中興大學 === 生物產業機電工程學系所 === 100 === A capillary electrophoresis (CE) microchip integrated with the electrochemical (EC) sensors has the advantages of easy miniaturization, portable convenience and fast separation/detection. The chip is widely used in the applications of separating and detecting the drugs, proteins and nucleic acids. In this study, a CE microchip capable of easily aligning the off-chip end-channel EC detectors was developed. The plexiglass fixer fabricated by CO2 laser ablation machine could fix the EC electrode microchip and the CE microchip together and allow the CE channel outlet to be easily aligned with the EC electrode. Moreover, the gap between two chips could be defined by the thickness of SU8 insulation layer of EC chips. The design can reduce the procedures and deviation of microscopic alignment. Using 3-cm long CE chip (effective separation length of 2.5 cm) with 30 μm gap between the CE outlet and the EC electrode under the separation field of 150 V/cm and the dual electrodes set at +0.7 V vs Ag/AgCl, the linear range and limit of detection (LOD) calculated by signal to noise (S/N) ratio (S/N=3) for dopamine (DA) was 1–100 μM and 250 nM, respectively, and for catechol (CAT) was 1–200 μM and 157 nM. When applying the redox cycling method with +0.7 V for oxidation and –0.4 V for reduction, the LOD of CAT could reach as low as 142 nM. The design of study can improve the alignment problem of the off-chip end-channel CE-EC chip, and process the advantages such as easy replacement of EC electrodes, long life-time of CE microchip and the improvement of detection characteristics.