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1996
Conference Paper
Titel
A micromachined open tubular reactor for immunosensor applications
Abstract
A micromachined open tubular reactor is presented, which was developed with special focus on the application in heterogeneous immunoassays such as the Enzyme Linked Immunosorbent Assay (ELISA). In contrary to previous designs, this device was realized in <100> silicon as a single channel and with one-side fluid connections. For the micromechanical fabrication a two side process employing SiC as an etch mask was developed. As a result, microreactors were produced with an internal volume of 27 mu l, which exhibit a meander-shaped channel at the chip frontside and two fluid ports on the backside. The meander is sealed with a pyrex cover by anodic bonding. During fabrication a silicon oxide layer with a high density of silanol groups is deposited at the inner reactor walls, resulting in a ready-to-use device for the covalent immobilization of immunoreceptors without the need of additional surface treatment. Due to the fact, that both fluid ports are located on the chip backside, the integr ation into a flow-through system is feasible with a simple snap-in mount. Tests of the reactor performance were done with a miniaturized toxin analyzer using T-2 toxin as a model analyte. In this system the microreactors showed a high signal reproducibility, a short analysis time and could be regenerated repeatedly. First experiments have shown an excellent stability of the immunological receptor layer, which is fully active and re-usable even after more than 20 regeneration cycles.