| AVS 54th International Symposium | |
| Biomaterial Interfaces | Friday Sessions |
| Session BI-FrM |
| Session: | Microbioanalytical Systems |
| Presenter: | F.A. Gomez, California State University, Los Angeles |
| Authors: | F.A. Gomez, California State University, Los Angeles A. Brown, California State University, Los Angeles M. Piyasena, California State University, Los Angeles A. Gaspar, California State University, Los Angeles S. Stevens, California State University, Los Angeles |
| Correspondent: | Click to Email |
In this paper, we describe the design and development of novel microfluidic devices (MDs) for electrophoretic and chromatographic separations. One study details our work on through-a-chip partial filling affinity capillary electrophoresis (PFACE) to estimate binding constants of ligands to receptors using as model systems carbonic anhydrase B (CAB, EC 4.2.1.1) and vancomycin from Streptomyces orientalis. Using multilayer soft lithography (MSL), a MD consisting of fluid and control channels is fabricated from poly(dimethylsiloxane) (PDMS) and fitted with an external capillary column. Multiple flow channels allow for manipulation of a zone of ligand and sample containing receptor and non-interacting standards into the MD and subsequently into the capillary column. Upon electrophoresis the sample components migrate into the zone of ligand where equilibrium is established. Changes in migration time of the receptor are used in the analysis to obtain a value for the binding interaction. In a second study we describe the development and study of a disposable and inexpensive MD, fabricated from PDMS incorporating conventional chromatographic reversed-phase silica particles (C18) without the use of frits, permanent physical barriers, tapers or restrictors. A novel external in-line magnetic valve allows for facile packing of the particles. Clamping- and anchor-effects providing the stability and the compactness of the packing were observed. A fiber optics assembly is incorporated onto the chip for detection of species. Food dyes and cephalosporin antibiotics were used to demonstrate the chromatographic applicability of this chip-based chromatographic packing.