Electroosmosis injection of blood serum into biocompatible microcapillary chip fabricated on quartz plate

A chip which allows the detection of various human health markers from a tr ace amount of blood has been studied. As a goal, a microcapillary with a 30 x 30 mum cross-section was fabricated using all-dry etching technologies o n a 2 x 2 cm SiO2 chip. The coating of the biocompatible 2-methacryloyloxye thylphosphorylcholine (MPC) polymer on the inner quartz wall of the microca pillary demonstrated a sufficiently long adsorption suppression of proteins in the serum on the quartz surface, while rapid stopping occurred for seru m injected into the microcapillary with a bare quartz surface. The latter r apid stopping corresponded well to fast electroosmosis flow due to the nega tively increasing zeta-potential by the adsorption of proteins on the quart z surface. The electroosmosis pump arranged a downstream of the microcapill ary was also developed to inject serum into it. As a preliminary applicatio n, a given concentration-standard solution was injected into the ion-sensit ive field-effect transistor (ISFET) embedded in the chip, employing the ele ctroosmosis pump arranged downstream of the sensor position. Hence, the pH and Na+ and K+ cation concentrations were measured.