Several anomalies, e.g., in peak shape, migration time, and baseline drift, all due to pressure-driven backflow, were previously reported to occur during serial injection on capillary electrophoresis (CE) chips. Since these anomalies were worse for polydimethylsiloxane (PDMS) microchips than for glass microchips, reproducible data on PDMS microchips were difficult to obtain. In this paper, we found that these problems were affected by the hydrophilic or hydrophobic properties of the reservoirs on the microchip and demonstrated that these anomalies were reduced by converting the hydrophobic properties of the reservoirs on the PDMS microchip into hydrophilic ones. Thus, compared with hydrophobic reservoirs, hydrophilic reservoirs were suitable for the formation of a stable plug. Several chip designs were suggested to reduce these pressure-driven backflows.
Bibliographical noteFunding Information:
The authors appreciate Kee Chun Shin at Digital Bio Technology. This work has been supported by the Intelligent Microsystem Program (IMP) of the 21st Century Frontier R&D Program sponsored by the Korea Ministry of Science and Technology and also by the Nano Bioelectronics and Systems Research Center of Seoul National University, which is an Engineering Research Center supported by the Korean Science and Engineering Foundation (KOSEF).
- Capillary electrophoresis
- Peak shape
ASJC Scopus subject areas
- Analytical Chemistry
- Organic Chemistry